High Breakdown Protection and Blinder Protection Films, Substrates and Processing Methods

Abstract

This invention discloses a high-displacement protective and anti-burr film, a substrate, and a processing method thereof. The high-displacement protective and anti-burr film includes a substrate layer, an adhesive layer, a rigid filler layer, and a surface contact layer. The adhesive layer is disposed on one surface of the substrate layer, and the rigid filler layer is disposed on the opposite surface of the adhesive layer. The rigid filler layer comprises a first thermoplastic material and a first inorganic filler, and has a surface hardness of not less than 6B. The surface contact layer is disposed on the opposite surface of the rigid filler layer, and comprises a modified acrylic resin, a second thermoplastic material, and a second inorganic filler, with an adhesive strength between 0.05 N / cm and 30 N / cm. This invention's high-displacement protective and anti-burr film simultaneously achieves the triple functions of high-displacement filling, drill-hole anti-burr, and residue-free peeling.

Description

Technical Field

[0001] This invention relates to the fields of semiconductor packaging and high-end circuit board manufacturing technology, and in particular to a high breakage protection and anti-burr film, substrate and its processing method. Background Technology

[0002] In high-precision manufacturing industries such as advanced semiconductor packaging, substrates, high-density interconnect printed circuit boards (PCBs), LEDs, and optoelectronic displays, substrate surfaces typically exhibit dense metal bumps, copper pillars, deep cavity blind vias, countersunk holes, and other high-displacement structures. When performing subsequent machining processes on such substrates with high-displacement structures (such as drilling processes like countersunk holes in ultra-thick backplanes), a temporary protective adhesive film must be applied to the substrate surface to protect the micro-circuit patterns and assist in the processing. This adhesive film is then physically peeled off.

[0003] However, when faced with complex high-partition morphology and harsh mechanical cutting stress, the protective film in the existing technology cannot simultaneously achieve seamless filling of high-partition surfaces, mechanical support under extreme processing, and zero interface contamination after the process.

[0004] The reason lies in the fact that traditional protection solutions often rely solely on homogeneous single colloidal systems or conventional double-layer base film structures. These traditional systems present inherent contradictions in their underlying physical properties: if a soft or highly fluid adhesive is used to fully cover and fill high-density bumps or deep cavities, the material will lose necessary mechanical rigidity. Under the pressure of high-speed mechanical cutting such as from drill bits, the adhesive film cannot provide sufficient compressive support for the orifice (i.e., insufficient pad clamping effect), inevitably leading to severe burrs and orifice deformation defects. Conversely, if the material hardness is simply increased to suppress burrs, the adhesive film cannot penetrate into the microscopic gaps, easily trapping air bubbles or causing poor coverage in high-displacement dead zones. Furthermore, after undergoing strong mechanical stress, the cohesive force of traditional colloidal systems is unevenly distributed. During the final peeling process, these tend to become embedded in deep holes or bump gaps, forming bumps and filaments, causing serious residual adhesive contamination problems.

[0005] Therefore, there is a need for a high-breakage protection and anti-burr film that combines high hardness to suppress burrs, low surface tack to avoid adhesive residue, and excellent filling capacity. Summary of the Invention

[0006] The main objective of this invention is to propose a high-displacement protection and anti-burr film, which aims to solve the technical problem in the prior art that the protective film cannot simultaneously achieve seamless filling of high-displacement surfaces, rigid support under extreme machining, and no residual adhesive peeling after the process.

[0007] To achieve the above objectives, the present invention proposes a high-breakage protection and anti-burr film, comprising a substrate layer, an adhesive layer, a rigid filler layer, and a surface contact layer, wherein...

[0008] An adhesive layer is disposed on one side surface of the substrate layer;

[0009] A rigid filler layer is disposed on the side surface of the adhesive layer opposite to the substrate layer. The rigid filler layer comprises a first thermoplastic material and a first inorganic filler, and the surface hardness of the rigid filler layer is not less than 6B.

[0010] A surface contact layer is disposed on the side of the rigid filler layer opposite to the adhesive layer. The surface contact layer comprises a modified acrylic resin, a second thermoplastic material, and a second inorganic filler, and the adhesive force of the surface contact layer is between 0.05 N / cm and 30 N / cm.

[0011] In one embodiment, the surface contact layer satisfies at least one of the following conditions:

[0012] The surface contact layer has de-adhesion properties, and the adhesive force after the surface contact layer is de-adhesion is not greater than 2 N / cm;

[0013] The surface hardness of the surface contact layer is not less than 6B;

[0014] The thickness of the surface contact layer is no greater than 0.1 mm.

[0015] In one embodiment, the rigid filler layer and / or the surface contact layer satisfy at least one of the following parameter conditions:

[0016] Shore hardness ranges from 5 Shore A to 55 Shore D;

[0017] Young's modulus ranges from 0.02 GPa to 1 GPa;

[0018] Tensile strength ranges from 2 MPa to 60 MPa;

[0019] The damage elongation rate ranges from 100% to 1500%.

[0020] In one embodiment, the thickness of the rigid filler layer is between 0.025 mm and 0.7 mm.

[0021] In one embodiment, the modified acrylic resin includes at least one of waterborne acrylic emulsion resin, rubber-blended modified acrylic resin, silicone-modified acrylic resin, hydrophilic modified acrylic resin, homopolymer acrylic resin, copolymer acrylic resin, and thermally crosslinked acrylic resin.

[0022] In one embodiment, the first thermoplastic material and / or the second thermoplastic material includes at least one of polyvinyl butyral, ethylene-vinyl acetate copolymer, thermoplastic polyurethane, thermoplastic polyester elastomer, polyolefin elastomer, thermoplastic vulcanized rubber, styrene-based thermoplastic elastomer, thermoplastic nitrile rubber, olefin block copolymer, ionic thermoplastic elastomer, polyamide-based thermoplastic elastomer, ethylene glycol copolymerized modified polyethylene terephthalate, and low-density polyethylene.

[0023] In one embodiment, the first inorganic filler and / or the second inorganic filler satisfy at least one of the following conditions:

[0024] It is selected from at least one of graphite, carbon black, graphene, fullerene, silicon dioxide, aluminum oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium silicate, silicon carbide, titanium carbide, titanium oxide, magnesium oxide, calcium oxide, boron nitride, aluminum nitride, and thermally expandable foaming materials;

[0025] The particle size ranges from 0.1 μm to 100 μm;

[0026] The surface is modified with at least one functional group selected from aniline, alkyl, nitrogen-containing functional group, double-bonded functional group and epoxy group.

[0027] In one embodiment, the adhesive layer comprises a vinyl chloride-vinyl acetate copolymer resin.

[0028] In one embodiment, the adhesive layer further comprises a hot-melt ethylene-vinyl acetate copolymer resin and / or an epoxy resin.

[0029] In one embodiment, when the adhesive layer comprises a hot-melt ethylene-vinyl acetate copolymer resin, the hot-melt ethylene-vinyl acetate copolymer resin includes at least one of reactive polyurethane hot melt adhesive, polyamide hot melt adhesive, polyolefin hot melt adhesive, ethylene-vinyl acetate copolymer hot melt adhesive, polyethylene hot melt adhesive, and polypropylene hot melt adhesive.

[0030] In one embodiment, when the adhesive layer further comprises an epoxy resin, the epoxy resin is selected from at least one of glycidylamine epoxy resin, phenoxy resin, polyfunctional o-cresol glycidyl ether epoxy resin, phenol-biphenyl epoxy resin, bisphenol F solid epoxy resin, isocyanate modified epoxy resin, naphthol epoxy resin, phenol-formaldehyde epoxy resin, semi-crystalline epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, liquid bisphenol S epoxy resin, and liquid phenolic epoxy resin.

[0031] In one embodiment, when the adhesive layer comprises epoxy resin, the adhesive layer further comprises phenolic resin as a curing agent for the epoxy resin, wherein the content of the phenolic resin satisfies the following dependency relationship:

[0032] Phenolic resin content = (hydroxyl equivalent of phenolic resin / epoxy equivalent of epoxy resin) × epoxy resin content.

[0033] In one embodiment, the adhesive layer satisfies at least one of the following conditions:

[0034] The content of the ethylene chloride-vinyl acetate copolymer resin is between 5 wt% and 100 wt% based on the total weight of the adhesive layer.

[0035] When the adhesive layer contains a hot-melt ethylene-vinyl acetate copolymer resin, the content of the hot-melt ethylene-vinyl acetate copolymer resin is not greater than 75 wt% based on the total weight of the adhesive layer.

[0036] When the adhesive layer contains epoxy resin, the epoxy resin content, based on the total weight of the adhesive layer, is no more than 20 wt%.

[0037] The thickness ranges from 0.0005 mm to 0.1 mm.

[0038] In one embodiment, the vinyl chloride-vinyl acetate copolymer resin satisfies at least one of the following parameters: chlorine content between 10% and 70%, vinyl acetate content between 5% and 50%, softening point between 40°C and 120°C, tensile strength not less than 1 MPa and elongation at break not less than 200%; and / or

[0039] The hot-melt ethylene-vinyl acetate copolymer resin meets at least one of the following parameters: vinyl acetate content between 18% and 33%, softening point between 40°C and 200°C, tensile strength not less than 1 MPa, and elongation at break not less than 200%.

[0040] In one embodiment, the substrate layer has a first surface and a second surface disposed opposite to each other;

[0041] The first surface is provided with an antistatic layer, the sheet resistivity of which is between 10Ω and 10Ω. 8 Ω;

[0042] The adhesive layer is disposed on the second surface, and the dyne value of the second surface is not less than 40.

[0043] In one embodiment, the substrate layer comprises at least one of polyethylene terephthalate, polyethylene naphthalate, polyetherimide, polyphenylene sulfide, polyetheretherketone, nylon, polycarbonate, poly(p-phenylenebenzodioxazole), polyimide, polysulfone, polyphenylene sulfone, liquid crystal polymer, polymethylpentene, polyethylene succinate, biaxially oriented polypropylene, polypropylene, high-density polyethylene, polyolefin, cyclic olefin copolymer, and bismaleimide triazine resin.

[0044] In one embodiment, the substrate layer satisfies at least one of the following parameters:

[0045] The surface roughness Ra of the second surface of the substrate layer is between 0.05 μm and 0.5 mm;

[0046] Shore hardness D not less than 60;

[0047] Surface hardness not less than HB;

[0048] Young's modulus ranges from 0.1 GPa to 30 GPa;

[0049] Tensile strength ranges from 10 MPa to 4000 MPa;

[0050] The thickness ranges from 0.009 mm to 0.3 mm.

[0051] In one embodiment, the high-displacement protection and anti-burr film further includes:

[0052] A release layer is peelably disposed on the surface of the surface contact layer on the side opposite to the rigid filler layer.

[0053] In one embodiment, the release layer satisfies at least one of the following conditions:

[0054] It contains at least one of polyethylene terephthalate, biaxially oriented polypropylene, polypropylene, high-density polyethylene, polyolefin and polyimide;

[0055] Release force ranges from 3 g / mm to 500 g / mm;

[0056] The thickness ranges from 0.0005 mm to 0.1 mm.

[0057] The present invention also proposes a substrate processing method using a high-breakage protection and anti-burr film as described in any of the preceding claims, the processing method comprising:

[0058] A substrate to be processed is provided, the surface of which has a high-discontinuity structure;

[0059] The high-displacement protection and anti-burr film are attached to the surface of the substrate, and the surface contact layer of the high-displacement protection and anti-burr film is bonded and filled to the high-displacement structure.

[0060] Drilling is performed on the substrate to which the high-breakage protection and anti-burr film is applied;

[0061] After the drilling process is completed, the high-displacement protection and anti-burr film is peeled off from the surface of the substrate.

[0062] In one embodiment, under heating and pressurization conditions, the high-breakage protection and anti-burr film is attached to the surface of the substrate; and

[0063] Before performing the drilling process, the high-break protection and anti-burr film attached to the substrate is cooled to room temperature.

[0064] In one embodiment, when the surface contact layer in the high-breakage protection and anti-burr film has debonding properties, the processing method further includes, after performing the drilling process and before peeling off the high-breakage protection and anti-burr film:

[0065] The high-displacement protection and anti-burr film is subjected to a de-adhesion activation treatment to reduce the adhesion force of the surface contact layer to no more than 2 N / cm.

[0066] In one embodiment, the high-displacement structure includes at least one of blind holes, countersunk holes, metal bumps, and copper pillars.

[0067] The present invention also provides a substrate, which is obtained by the substrate processing method described in any of the preceding claims.

[0068] The high-displacement protective and anti-burr film provided in this application resolves the contradiction between filling properties, anti-burr properties, and peel cleanliness in traditional single colloidal systems at the physical level by spatially decoupling the rigid filler layer and the surface contact layer. It has the following beneficial effects:

[0069] First, the rigid filler layer undergoes controlled plastic flow during heating and pressurization. The first thermoplastic material inside drives the first inorganic filler to penetrate and fill the micro-recessed structures such as blind holes, countersunk holes, or gaps between metal bumps on the substrate surface. After cooling, it forms a rigid filler that is tightly fitted with the high-displacement morphology, establishing a continuous physical support surface between the adhesive film and the substrate surface. This eliminates the weak areas where the drill bit is suspended or insufficiently supported during drilling, and physically suppresses the generation of burrs and hole deformation defects.

[0070] Second, the adhesive force of the surface contact layer is precisely limited to the range of 0.05 N / cm to 30 N / cm. During peeling, the peeling interface stably propagates along the contact surface between the surface contact layer and the substrate surface, rather than undergoing cohesive fracture within the surface contact layer. This deterministic interface separation path ensures that the substrate surface remains clean after the adhesive film is removed, effectively solving the problem of residual adhesive in high-gap gaps caused by uneven distribution of cohesive strength in traditional UV anti-adhesive systems.

[0071] Third, the stress dispersion network formed by the first inorganic filler in the rigid filling layer and the rigid support point of the second inorganic filler in the surface contact layer form a double-layer progressive stress transmission and dispersion system in the Z-axis direction. The impact force of the drill bit pressing down is converted into a distributed surface load. The hole wall material is always in a constrained and compressed state throughout the entire processing process, realizing the synergistic optimization of the triple performance of filling, mechanical rigidity and peeling cleanliness. Attached Figure Description

[0072] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0073] Figure 1 This is a schematic diagram of the structure of an embodiment of the high breakage protection and anti-burr film of the present invention;

[0074] Figure 2 This is a schematic flowchart of an embodiment of the substrate processing method of the present invention.

[0075] Explanation of icon numbers:

[0076] 10. Substrate layer; 20. Adhesive layer; 30. Rigid filler layer; 40. Surface contact layer; 50. Release layer

[0077] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0078] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0079] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0080] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0081] This invention proposes a high-breakage protection and anti-burr film.

[0082] In embodiments of the present invention, such as Figure 1 As shown, the high-breakage protection and anti-burr film includes a substrate layer 10, an adhesive layer 20, a rigid filler layer 30, a surface contact layer 40, and a release layer 50. This multi-layered composite structure spatially decouples the two core functions of "rigid mechanical support" and "low-viscosity interface separation," resolving the physical property contradictions between filling properties, anti-burr properties, and peel cleanliness in traditional single colloidal systems.

[0083] Specifically, the adhesive layer 20 is disposed on one side surface of the substrate layer 10. The substrate layer 10 serves as the rigid mechanical framework of the entire adhesive film, providing stable dimensional support and tension maintenance during subsequent processes such as vacuum hot pressing, drilling, and peeling. The adhesive layer 20 establishes a strong interlayer bond between the substrate layer 10 and the rigid filler layer 30, preventing interlayer peeling or slippage during processing.

[0084] Specifically, a rigid filler layer 30 is disposed on the side surface of the adhesive layer 20 facing away from the substrate layer 10. The rigid filler layer 30 comprises a first thermoplastic material and a first inorganic filler, and the surface hardness of the rigid filler layer 30 is not less than 6B.

[0085] In this process, the first thermoplastic material forms a continuous phase network in the rigid filler layer 30. Its main function is to give the layer film-forming flexibility and processing fluidity in the uncured or semi-cured state, so that the rigid filler layer 30 can generate controlled plastic flow when heated and pressed, thereby penetrating and filling the high discontinuity morphology of the substrate surface.

[0086] The first inorganic filler is uniformly distributed in the continuous phase network in the form of a dispersed phase. Its main function is to form a dense stress dispersion network in three-dimensional space by virtue of its own rigid skeleton structure, and to embed itself in the microscopic recessed structure on the substrate surface after bonding, providing continuous rigid support for subsequent drilling. When the rigid filler layer 30 is subjected to point-like downward impact from the drill bit during drilling, the stress dispersion network forcibly transforms the point stress into a planar stress field, thereby suppressing the local plastic deformation of the rigid filler layer 30.

[0087] Specifically, the rigid filler layer 30 is configured to fill the high discontinuity morphology of the substrate surface after bonding, and with a surface hardness of not less than 6B, it applies a pad clamping effect to the hole edge during drilling, thereby physically suppressing the generation of burrs.

[0088] Furthermore, a surface contact layer 40 is disposed on the side of the rigid filler layer 30 facing away from the adhesive layer 20. The surface contact layer 40 comprises a modified acrylic resin, a second thermoplastic material, and a second inorganic filler, and the adhesive force of the surface contact layer 40 is between 0.05 N / cm and 30 N / cm.

[0089] In this process, the modified acrylic resin serves as the main resin matrix of the surface contact layer 40. Its main function is to provide the initial adhesion force of the layer to the substrate surface, and through the physical anchoring formed between the polar groups in its molecular chain segments and the substrate surface, the adhesive film can be stably attached to the substrate surface during the application, transfer and alignment process.

[0090] The second thermoplastic material plays a role in toughening and regulating the cohesive strength of the surface contact layer 40, so that the surface contact layer 40 exhibits appropriate elastic yield when subjected to drill bit impact, thus avoiding brittle cracking.

[0091] The second inorganic filler is distributed in the surface contact layer 40 in the form of dispersed particles. Its main function is to serve as a micro-rigid support point to ensure that the surface contact layer 40 does not deform excessively when subjected to Z-axis mechanical stress, and to effectively transmit the stress applied by the drill bit to the rigid filler layer 30 below.

[0092] Furthermore, the adhesive force of the surface contact layer 40 is precisely controlled within the aforementioned specific range. The lower limit of this adhesive force range ensures that the adhesive film can establish sufficient initial adhesion to the substrate surface during the application stage, preventing spontaneous detachment or localized warping during transfer and alignment. The upper limit of this adhesive force range physically locks the interface separation path during peeling—below this adhesive force boundary, when the adhesive film is removed, the peeling interface propagates along the contact surface between the surface contact layer 40 and the substrate surface, rather than undergoing cohesive destruction within the surface contact layer 40, leaving no adhesive residue on the substrate surface after peeling.

[0093] Specifically, the release layer 50 is peelably disposed on the side of the surface contact layer 40 facing away from the rigid filler layer 30. Specifically, the release layer 50 is the outermost layer in the adhesive film stack, serving as a physical protective barrier for the surface contact layer 40 during the manufacturing, storage, and transportation stages of the adhesive film. The modified acrylic resin contained in the surface contact layer 40 has a certain surface tackiness at room temperature. If directly exposed to air during storage or transportation, it easily adsorbs particles, fibers, or moisture from the environment, resulting in foreign matter being trapped between the surface contact layer 40 and the substrate surface during adhesion, affecting adhesion uniformity and peel cleanliness. The release layer 50, through its controllable release interface with the surface contact layer 40, physically isolates the surface contact layer 40 from the external environment. Removing the release layer 50 before use exposes a clean and intact adhesive surface.

[0094] When the release interface between the release layer 50 and the surface contact layer 40 is peeled off before the bonding process, the peeling interface propagates along the contact surface between the release layer 50 and the surface contact layer 40, and the release layer 50 is completely removed without leaving any release agent or film fragments on the surface of the surface contact layer 40. After the release layer 50 is removed, the adhesion and surface properties of the surface contact layer 40 are not affected and remain consistent with those when the release layer 50 is not used.

[0095] It is understandable that by spatially decoupling the rigid filler layer 30 from the surface contact layer 40, the high-displacement protection and anti-burr film of this application resolves the contradiction between filling, anti-burr and peeling cleanliness in traditional single colloidal systems at the physical level.

[0096] Specifically, when the adhesive film is heated and pressurized and adhered to the surface of a substrate with a high-displacement morphology, the rigid filler layer 30 undergoes controlled plastic flow under the combined drive of heat and pressure. The first thermoplastic material within it softens and deforms at the bonding temperature, driving the first inorganic filler to permeate into the microscopic recesses on the substrate surface, such as blind holes, countersunk holes, or gaps between metal bumps. After cooling to room temperature, it forms a rigid filler that is tightly fitted to the high-displacement morphology. This fitting creates a continuous physical support surface between the adhesive film and the substrate surface in geometric space, eliminating weak areas where the drill bit is suspended or insufficiently supported during drilling. In subsequent mechanical drilling, the rotary cutting force of the drill bit is evenly distributed across the entire filler support surface, effectively resolving local stress concentrations at the hole edge, thereby physically suppressing the generation of burrs and hole deformation defects.

[0097] Meanwhile, the adhesive force between the surface contact layer 40 and the substrate surface is precisely limited to the range of 0.05 N / cm to 30 N / cm. When drilling is completed and the peeling action is performed, this upper limit of adhesive force allows the peeling stress to propagate along the physical contact surface between the surface contact layer 40 and the substrate surface. The peeling interface is stably formed at this contact surface, rather than undergoing cohesive fracture within the surface contact layer 40. The determinacy of this interface separation path ensures that the peeling of the adhesive film leaves no visible or microscopic adhesive residue on the substrate surface, and the substrate surface maintains the same cleanliness as before adhesion after the adhesive film is removed. Thus, this application effectively eliminates the problem of high gap adhesive residue contamination caused by the deterioration of the crosslinking network or uneven distribution of cohesive strength in traditional UV anti-tack adhesive systems.

[0098] Furthermore, in the Z-axis direction, the surface hardness of the rigid filler layer 30 is not less than 6B. The stress dispersion network formed by the first inorganic filler within it transforms the concentrated compressive stress into a distributed surface load when impacted by the drill bit, thereby forming a stable pad-like clamping effect around the hole opening. The second inorganic filler contained in the surface contact layer 40 acts as a microscopic rigid support point, transmitting the Z-axis mechanical stress applied by the drill bit downwards to the rigid filler layer 30. This dual-layer progressive stress dispersion and support prevents the instantaneous shear force generated by the drill bit when penetrating the substrate from concentrating locally at the hole opening edge, ensuring that the hole wall material remains under constrained pressure. Through this synergistic mechanism, this application effectively suppresses burrs on high-partition substrates during mechanical drilling, while simultaneously ensuring low residual adhesive performance at the interface after peeling. This allows the contradictory performance indicators of filling properties, mechanical rigidity, and peeling cleanliness, previously found in traditional single-adhesive systems, to be synergistically achieved in the same adhesive film.

[0099] In some embodiments, the thickness of the rigid filler layer 30 is between 0.025 mm and 0.7 mm (e.g., 0.025 mm, 0.03 mm, 0.07 mm, 0.1 mm, 0.3 mm, 0.5 mm, 0.6 mm, 0.7 mm, etc.), preferably between 0.05 mm and 0.6 mm.

[0100] Specifically, the minimum thickness of the rigid filler layer 30 is strictly limited to not less than 0.025 mm. From a rheological and macroscopic topological perspective, this minimum thickness ensures that the layer contains sufficient volume of rheotropic resin matrix and densely packed inorganic filler particles when facing high-displacement morphologies such as dense metal bumps, copper pillars, or deep cavities / blind holes on the substrate surface to be processed. When the adhesive film is attached to the substrate surface under heating and pressurization conditions, a physical thickness of not less than 0.025 mm generates sufficient tangential fluid compression resistance, thereby completely encapsulating and filling the high-displacement structure in situ. Simultaneously, during subsequent drilling, this physical thickness provides a minimum elastic deformation buffer depth, combined with a surface hardness of not less than 6B, preventing high-speed drill bits from directly piercing or scratching the underlying adhesive layer and substrate layer 10.

[0101] By physically limiting this thickness, the rigid filler layer 30 can spontaneously eliminate poor coverage at high-displacement dead angles, prevent interface bubble defects, and ensure seamless adhesion of the interface before the processing.

[0102] Furthermore, the thickness of the rigid filler layer 30 is controlled to be no more than 0.7 mm. From a thermal and fracture mechanics perspective, this thickness limit is to prevent excessive thermal resistance and stress concentration during vacuum hot-pressing and subsequent drilling processes. If the thickness of the rigid filler layer 30 exceeds the physical boundary of 0.7 mm, on the one hand, heat cannot be conducted downwards promptly and evenly within the limited bonding time, resulting in insufficient resin rheological softening; on the other hand, an excessively thick adhesive layer, due to its excessive flowable volume, is prone to uncontrolled overflow under specific hot-pressing gravity conditions, leading to excessive overflow towards the inner wall edge of the hole and even large-area contamination of the microcircuit of the substrate to be processed.

[0103] By physically limiting this thickness, the rigid filler layer 30 can maintain the high rigidity pad effect while controlling the overall deformation volume and process thermal resistance within an excellent processing window, thus achieving precise control over the amount of adhesive overflow and effectively preventing excessive resin overflow from contaminating the substrate surface.

[0104] In some embodiments, the surface contact layer 40 has de-adhesion properties, and the adhesive force of the surface contact layer 40 after de-adhesion is not greater than 2 N / cm.

[0105] Specifically, the modified acrylic resin contained in the surface contact layer 40 is configured to undergo chemical or physical cross-linking under the action of a debonding activation treatment, so that the adhesive force of the surface contact layer 40 is reduced from the initial range of 0.05 N / cm to 30 N / cm to no more than 2 N / cm.

[0106] For example, the debonding activation treatment can be ultraviolet irradiation or heat treatment. Taking ultraviolet irradiation as an example, photosensitive functional groups are introduced into the molecular chain segments of the modified acrylic resin. After being irradiated with ultraviolet light of a specific wavelength, the photosensitive functional groups induce a cross-linking reaction inside the resin matrix, causing the free volume of the resin to shrink and the surface energy to decrease. As a result, the physical anchoring effect between the surface contact layer 40 and the substrate surface is significantly weakened, and the adhesion force is greatly reduced.

[0107] Taking heat treatment as an example, the modified acrylic resin is mixed with thermally expanding microspheres or thermally decomposing foaming agents. After being heated to a specific temperature, the microspheres or foaming agents expand in volume or decompose to produce gas, forming microscopic undulations at the contact interface between the surface contact layer 40 and the substrate surface, reducing the actual contact area and thus reducing the adhesion.

[0108] After drilling is completed and before peeling, the adhesive film is subjected to the above-mentioned debonding activation treatment. After the adhesion of the surface contact layer 40 is reduced to no more than 2 N / cm, only a very small mechanical tearing force is required to completely remove the adhesive film from the substrate surface during peeling. The peeling interface is stably formed at the contact surface between the surface contact layer 40 and the substrate surface, further reducing the risk of residual adhesive.

[0109] It is understandable that by configuring the surface contact layer 40 with de-adhesion properties and limiting the degree of de-adhesion with a quantitative parameter that the adhesive force after de-adhesion is no more than 2 N / cm, the adhesive film can be firmly attached to the substrate surface with a high initial adhesive force during the application and processing stages. After processing, the adhesion can be greatly weakened by a simple excitation treatment. This balances the dual requirements of application stability during processing and low damage and no adhesive residue during peeling.

[0110] In some embodiments, the surface hardness of the surface contact layer 40 is not less than 6B.

[0111] Specifically, surface hardness is achieved by controlling the content and dispersion state of the second inorganic filler in the surface contact layer 40. The second inorganic filler is uniformly distributed in the resin matrix composed of modified acrylic resin and the second thermoplastic material in the form of dispersed particles. The higher the content and the better the dispersion uniformity of the second inorganic filler, the higher the surface hardness of the surface contact layer 40.

[0112] During drilling, the surface hardness of the surface contact layer 40 is not less than 6B, ensuring that the layer does not undergo excessive deformation at the moment of drill bit pressure. As the contact interface between the adhesive film and the substrate, the surface hardness of the surface contact layer 40 directly affects the stress state at the hole edge during the initial drill bit entry. When the surface hardness of the surface contact layer 40 is less than 6B, the layer collapses locally at the moment of drill bit pressure, the substrate material at the hole edge loses effective support, and burrs are generated along the hole edge. However, when the surface hardness of the surface contact layer 40 is not less than 6B, the layer provides a stable rigid support surface for the hole edge, uniformly transmitting the initial downward pressure applied by the drill bit to the underlying rigid filler layer 30, together forming a progressive anti-deformation support system.

[0113] It is understandable that by limiting the surface hardness of the surface contact layer 40 to no less than 6B, the surface contact layer 40 can not only perform the function of low-viscosity interface separation, but also have the mechanical rigidity to participate in the anti-burr support during drilling. This lower limit of hardness corresponds to the surface hardness of the rigid filling layer 30 being no less than 6B, forming a double-layer rigid protection in the Z-axis direction. The edge of the borehole is constrained and supported throughout the entire process from drill bit contact to drill bit penetration, thus suppressing the generation of burrs.

[0114] In some embodiments, the thickness of the surface contact layer 40 is no greater than 0.1 mm.

[0115] Specifically, the thickness of the surface contact layer 40 is controlled by the amount of coating during the coating or lamination process. The thickness of the surface contact layer 40 has a dual impact on its function. On the one hand, the surface contact layer 40 needs to be thick enough to cover the second inorganic filler particles inside and provide sufficient surface wetting and contact area during attachment. On the other hand, excessive thickness of the surface contact layer 40 will have two adverse consequences. First, an excessively thick surface contact layer 40 forms an excessively long stress transmission path in the Z-axis direction. When the drill bit presses down, the compressibility deformation of the layer itself increases, resulting in a decrease in the efficiency of stress transmission to the rigid filler layer 30, weakening the synergistic effect of the double-layer support system. Second, when the surface contact layer 40 is peeled off, its internal cohesive strength may be insufficient to withstand the peeling pull, resulting in cohesive failure within the layer and the generation of residual adhesive.

[0116] The thickness of the surface contact layer 40 is limited to no more than 0.1 mm, so that while the layer meets the basic functional requirements of coating the filler and providing surface wetting, the stress transmission path along the Z-axis is controlled within a reasonable range, and the stress transfer between the rigid filler layer 30 and the surface contact layer 40 remains efficient. For example, the thickness of the surface contact layer 40 can be 0.01 mm, 0.03 mm, 0.05 mm, 0.08 mm, or 0.1 mm.

[0117] It is understandable that by limiting the thickness of the surface contact layer 40 to no more than 0.1 mm, the surface wetting function and stress transmission efficiency of the layer are balanced in geometric space. While ensuring sufficient contact with the substrate surface during the bonding stage, the transmission distance of Z-axis stress during drilling is shortened, so that the instantaneous impact force applied by the drill bit can be efficiently transmitted to the rigid filler layer 30 for dispersion and dissipation. At the same time, the risk of cohesive failure due to excessive layer thickness during peeling is reduced.

[0118] In some embodiments, the Shore hardness of the rigid filler layer 30 and / or the surface contact layer 40 is between 5 Shore A and 55 Shore D.

[0119] Specifically, the Shore hardness of the rigid filler layer 30 and the surface contact layer 40 directly affects the mechanical behavior of the adhesive film during high-displacement filling and drilling support processes. A lower Shore hardness of 5 Shore A ensures that the rigid filler layer 30 and the surface contact layer 40 possess sufficient flexibility during the bonding stage, allowing them to conform to the uneven surface of the substrate under heat and pressure, penetrating and filling to the bottom of blind vias, countersunk holes, or bump gaps, squeezing out residual air from microscopic depressions. An upper Shore hardness of 55 Shore D ensures that the rigid filler layer 30 and the surface contact layer 40 possess sufficient rigidity after curing or cooling, providing a stable compressive support surface for the hole edges during drilling. If the Shore hardness is below 5 Shore A, the material is too soft, and the layer itself undergoes significant plastic flow when the drill bit is pressed down, resulting in the hole losing effective support. If the Shore hardness is above 55 Shore D, the material stiffness is too high, and it cannot fully fill the high-displacement gap during bonding. The remaining gaps at the bonding interface become stress concentration points around the gaps during drilling, which in turn exacerbates the generation of burrs.

[0120] By limiting the Shore hardness range to 5 Shore A to 55 Shore D, the rigid filler layer 30 and the surface contact layer 40 exhibit differentiated mechanical responses during the application and filling stage and the drilling support stage, respectively—soft and compliant during application, and rigidly supportive during drilling. The mechanical requirements of both stages are harmoniously met within the same material system. For example, the Shore hardness of the rigid filler layer 30 and / or the surface contact layer 40 can be 10 Shore A, 20 Shore A, 40 Shore A, 60 Shore A, 80 Shore A, 10 Shore D, 25 Shore D, or 45 Shore D.

[0121] It is understood that by limiting the Shore hardness of the rigid filler layer 30 and / or the surface contact layer 40 to the aforementioned specific range, a phased adaptive matching of adhesion compliance and drilling rigidity is achieved at the physical level, which ensures both sufficient filling of the high-displacement morphology during bonding and stable support for the hole edge during drilling.

[0122] In some embodiments, the Young's modulus of the rigid filler layer 30 and / or the surface contact layer 40 is between 0.02 GPa and 1 GPa.

[0123] Specifically, Young's modulus characterizes a material's ability to resist deformation during the elastic deformation stage. A lower limit of 0.02 GPa ensures that the rigid filler layer 30 and surface contact layer 40 can undergo moderate elastic deformation when impacted by a drill bit, absorbing some of the impact energy and preventing direct transmission of the impact force to the substrate, thus avoiding substrate damage or component breakage. An upper limit of 1 GPa ensures that the rigid filler layer 30 and surface contact layer 40 maintain sufficient structural stiffness within the elastic deformation range, preventing permanent deformation beyond the elastic recovery range at the orifice edge when the drill bit is pressed down. If the Young's modulus is below 0.02 GPa, the material is too soft, resulting in excessive deformation of the layer itself at the moment of drill bit contact, causing the substrate material at the orifice edge to curl outwards due to lack of constraint. If the Young's modulus is above 1 GPa, the material is too rigid, and the impact energy cannot be dissipated through elastic deformation; instantaneous stress concentration may lead to microcracks in the substrate or component.

[0124] By limiting the Young's modulus to the range of 0.02 GPa to 1 GPa, the rigid filler layer 30 and the surface contact layer 40 behave as an elasto-plastic buffer layer under the impact load of drilling—absorbing the impact with moderate elastic deformation and maintaining the orifice constraint with sufficient rigidity. For example, the Young's modulus of the rigid filler layer 30 and / or the surface contact layer 40 can be 0.05 GPa, 0.1 GPa, 0.3 GPa, 0.5 GPa, 0.7 GPa, or 0.9 GPa.

[0125] It is understood that by limiting the Young's modulus of the rigid filler layer 30 and / or the surface contact layer 40 to the aforementioned specific range, an elastoplastic balance is achieved at the mechanical response level—absorbing drill bit impact energy to protect the substrate while maintaining constraint on the orifice material to suppress burrs.

[0126] In some embodiments, the tensile strength of the rigid filler layer 30 and / or the surface contact layer 40 is between 2 MPa and 60 MPa.

[0127] Specifically, tensile strength determines the ability of the rigid filler layer 30 and the surface contact layer 40 to resist fracture under tensile stress. A lower limit of 2 MPa ensures that the rigid filler layer 30 and the surface contact layer 40 possess sufficient cohesive strength to prevent intralayer fracture during peeling, thus avoiding adhesive residue on the substrate surface. An upper limit of 60 MPa ensures that the rigid filler layer 30 and the surface contact layer 40 maintain sufficient cohesive strength without excessively high peeling force, allowing the peeling operation to be completed smoothly with appropriate tension. If the tensile strength is below 2 MPa, the cohesive force of the layer itself is insufficient to resist the peeling force during peeling, and the fracture surface propagates within the layer, leaving debris in the microscopic depressions on the substrate surface. If the tensile strength is above 60 MPa, a large mechanical force is required during peeling, which may cause mechanical damage to the substrate or components.

[0128] The tensile strength is limited to a range of 2 MPa to 60 MPa, allowing the rigid filler layer 30 and the surface contact layer 40 to be removed as a single, complete film layer during peeling. The peeling interface propagates along the contact surface with the substrate, rather than undergoing cohesive failure within the layer. For example, the tensile strength of the rigid filler layer 30 and / or the surface contact layer 40 can be 5 MPa, 15 MPa, 25 MPa, 35 MPa, 45 MPa, or 55 MPa.

[0129] It is understood that by limiting the tensile strength of the rigid filler layer 30 and / or the surface contact layer 40 to the aforementioned specific range, the interface separation path is locked at the peeling behavior level—the film layer with sufficient cohesive strength to resist the peeling pull is removed as a whole, and the peeling interface is limited to the contact surface between the film layer and the substrate, thus ensuring the cleanliness of the interface after peeling.

[0130] In some embodiments, the breaking elongation of the rigid filler layer 30 and / or the surface contact layer 40 is between 100% and 1500%.

[0131] Specifically, the breaking elongation characterizes the degree of plastic deformation that a material can withstand before fracture. A lower limit of 100% for the breaking elongation ensures that the rigid filler layer 30 and the surface contact layer 40 possess sufficient flexibility, allowing them to undergo moderate tensile deformation during bonding, conforming to high-displacement morphologies and tightly adhering to complex geometric locations such as blind hole sidewalls and bump roots. An upper limit of 1500% for the breaking elongation ensures that the rigid filler layer 30 and the surface contact layer 40 possess sufficient ductility without becoming excessively soft and undergoing uncontrolled flow deformation during drilling. If the breaking elongation is below 100%, the material lacks sufficient deformation capacity during bonding and cannot adequately fill micro-gaps, leaving unfilled voids at the bonding interface. If the breaking elongation is above 1500%, the material may experience excessive plastic drag under the shear force of drilling, resulting in stringing or curling at the hole edges.

[0132] The range of elongation at break is limited to 100% to 1500%, ensuring that the rigid filler layer 30 and the surface contact layer 40 have sufficient ductility to fill complex topography during bonding and maintain shape stability to provide effective support during drilling. For example, the elongation at break of the rigid filler layer 30 and / or the surface contact layer 40 can be 150%, 300%, 500%, 800%, 1000%, or 1300%.

[0133] It is understood that by limiting the failure elongation of the rigid filler layer 30 and / or the surface contact layer 40 to the aforementioned specific range, a balance between elongation filling and shape retention is achieved in terms of deformation capability—fully elongating during attachment to seamlessly cover the high-displacement structure, and maintaining the geometry during drilling to stably support the orifice material.

[0134] In some embodiments, the modified acrylic resin contained in the surface contact layer 40 includes at least one of waterborne acrylic emulsion resin, rubber-blended modified acrylic resin, silicone-modified acrylic resin, hydrophilic modified acrylic resin, homopolymer acrylic resin, copolymer acrylic resin, and thermally crosslinked acrylic resin.

[0135] Specifically, the various modified acrylic resins described above play different functional roles in the surface contact layer 40. Waterborne acrylic emulsion resins use water as the dispersion medium. After film formation, the polar functional groups such as carboxyl or hydroxyl groups distributed on the surface form a physical anchor between the surface and the metal oxide layer or polar dielectric layer on the substrate, giving the surface contact layer 40 a suitable initial adhesion force. Rubber-blended modified acrylic resins disperse the rubber phase in the continuous acrylic resin phase in a microscopic "island structure." When subjected to tensile or shear stress, the rubber phase acts as a stress absorption point to dissipate energy, delaying crack propagation and enhancing the cohesive integrity of the surface contact layer 40 during peeling. Organosilicon-modified acrylic resins, through the low surface energy interface layer formed by the migration and enrichment of siloxane segments to the surface during film formation, enable the surface contact layer 40 to maintain low adhesion force without relying on debonding activation treatment, while also giving the surface contact layer 40 thermal stability under high-temperature processing environments. Hydrophilic modified acrylic resin enhances the initial wettability of the surface contact layer 40 to the substrate by introducing polyethylene glycol segments or hydrophilic groups such as hydroxyl and carboxyl groups, and maintains stable adhesion in a humidity-fluctuating environment through water absorption-loss balance.

[0136] Homopolymer acrylic resins, represented by polybutyl acrylate or polyisooctyl acrylate, possess low glass transition temperatures, allowing the surface contact layer 40 to exhibit good surface wetting and initial tack at room temperature, enabling it to establish sufficient contact with the substrate surface without additional heating during application. Copolymer acrylic resins are copolymerized from multiple acrylate monomers. By adjusting the type and ratio of comonomers, the glass transition temperature, polarity, and crosslinking activity of the resin can be tailored at the molecular level, providing flexible technical means for multi-dimensional performance optimization of the surface contact layer 40. Thermally crosslinked acrylic resins maintain a linear molecular configuration during coating and application, exhibiting sufficient thermal fluidity to wet the substrate surface. During the post-application heating stage, the crosslinking agent activates chemical crosslinking between resin molecular chains, significantly improving the cohesive strength and Young's modulus of the surface contact layer 40, achieving a phased performance evolution of "flow first, then cure."

[0137] It is understood that by limiting the modified acrylic resin to at least one of the above types, the surface contact layer 40 can be selected or compounded in a targeted manner according to the substrate material, processing temperature and peeling requirements, so as to achieve synergistic optimization in the three processing stages of attachment filling, drilling support and peeling cleanliness.

[0138] In some embodiments, the first thermoplastic material and / or the second thermoplastic material includes at least one of polyvinyl butyral, ethylene-vinyl acetate copolymer, thermoplastic polyurethane, thermoplastic polyester elastomer, polyolefin elastomer, thermoplastic vulcanized rubber, styrene-based thermoplastic elastomer, thermoplastic nitrile rubber, olefin block copolymer, ionic thermoplastic elastomer, polyamide-based thermoplastic elastomer, ethylene glycol copolymerized modified polyethylene terephthalate, and low-density polyethylene.

[0139] Specifically, the aforementioned thermoplastic materials all serve to form a continuous phase network in the rigid filler layer 30 and the surface contact layer 40. The flexibility of their molecular chain segments, the content of polar groups, and the thermal transition temperature directly affect the film-forming properties, adhesion flowability, and mechanical response behavior of the layer.

[0140] Functionally, polyvinyl butyral, ethylene-vinyl acetate copolymer, and thermoplastic nitrile rubber belong to polar thermoplastic materials. Polyvinyl butyral contains both butyral and hydroxyl groups in its molecular chain, exhibiting excellent wetting and physical adhesion to the surfaces of inorganic fillers and the metal or dielectric surfaces of the substrate, thus contributing to the uniform dispersion of the first inorganic filler in the rigid filler layer 30. The ethylene-vinyl acetate copolymer allows for wide-range control of softness and polarity by adjusting the vinyl acetate content; higher vinyl acetate content facilitates bonding and filling, while lower content improves modulus. Thermoplastic nitrile rubber, with its strong polar anchoring effect on metal surfaces through the nitrile groups in the acrylonitrile segments, assists in establishing reliable initial adhesion in the surface contact layer 40 and maintains film integrity with good elastic recovery during peeling.

[0141] Thermoplastic polyurethanes, thermoplastic polyester elastomers, styrene-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers belong to the block copolymer type of thermoplastic elastomers. A common characteristic of these materials is that their molecular chains consist of alternating hard and soft segments. The hard segments provide strength by agglomerating through hydrogen bonding or crystallization to form physical crosslinking points, while the soft segments provide flexibility and elastic recovery. Thermoplastic polyurethanes and thermoplastic polyester elastomers, in particular, can have their modulus and elasticity controlled over a wide range by adjusting the hard-to-soft segment ratio, making them suitable for mechanical reinforcement of rigid filler layers 30 or toughening modification of surface contact layers 40. The hard amide groups in polyamide-based thermoplastic elastomers impart excellent heat and chemical resistance, making them suitable for high-temperature drilling or processing involving contact with chemical coolants. Styrene-based thermoplastic elastomers melt and flow during the heating stage of application to assist filling, and after cooling, they return to their elastomeric state to provide elastic support.

[0142] Polyolefin elastomers, olefin block copolymers, and low-density polyethylene belong to the category of non-polar polyolefin thermoplastic materials. A common characteristic of these materials is the absence of strongly polar groups in their molecular chains, resulting in low surface energy. Introducing non-polar polyolefins into the surface contact layer 40 can reduce the adhesion to the substrate to a reasonable range without relying on debonding activation treatment, which is beneficial for reducing tear resistance during peeling and maintaining the integrity of the film morphology after peeling. Olefin block copolymers, through the alternating arrangement of hard crystalline blocks and soft amorphous blocks, exhibit superior heat resistance and elastic recovery compared to traditional random copolymer polyolefins while maintaining low density.

[0143] Thermoplastic vulcanizates and ionic thermoplastic elastomers belong to the category of physically cross-linked thermoplastic elastomers. Thermoplastic vulcanizates disperse cross-linked rubber particles within a continuous thermoplastic phase through dynamic vulcanization, combining the high elasticity of rubber with the hot processability of thermoplastics, effectively improving the impact toughness of the layer. Ionic thermoplastic elastomers form a temperature-reversible physically cross-linked network through electrostatic association between ionic groups—when heated to the processing temperature, the ionic association dissociates, and the material regains its fluidity to fill high-displacement gaps; upon cooling, the cross-linked network is re-established, providing structural support for drilling.

[0144] Ethylene glycol copolymerized modified polyethylene terephthalate (PET) is a modified polyester thermoplastic material. Copolymerization modification reduces the crystallinity and crystallization rate of PET, providing moderate flexibility while maintaining a certain rigidity, which is beneficial for conforming to high-partial morphology during bonding.

[0145] It is understood that by limiting the first thermoplastic material and / or the second thermoplastic material to at least one of the above types, the rigid filler layer 30 and the surface contact layer 40 can be independently selected or compounded according to their respective functional emphases—the rigid filler layer 30 emphasizes the balance between filling compliance and rigid support, and the surface contact layer 40 emphasizes the balance between initial adhesion and peel integrity—to achieve synergistic performance optimization in the three stages of adhesion, drilling and peeling.

[0146] In some embodiments, the first inorganic filler and / or the second inorganic filler are selected from at least one of graphite, carbon black, graphene, fullerene, silicon dioxide, aluminum oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium silicate, silicon carbide, titanium carbide, titanium oxide, magnesium oxide, calcium oxide, boron nitride, aluminum nitride, and thermally expandable foaming materials.

[0147] Specifically, the aforementioned inorganic fillers can be classified into four categories according to their chemical properties and functions: carbon-based fillers, oxide and hydroxide fillers, nitride and carbide fillers, and functional fillers.

[0148] Carbon-based fillers include graphite, carbon black, graphene, and fullerene. These fillers share the common characteristic of excellent thermal conductivity and self-lubricating properties. Introducing carbon-based fillers into the rigid filler layer 30 allows for the rapid dissipation of localized heat generated by drill bit rotational friction along the filler network during drilling, reducing heat accumulation at the borehole edge. The layered or spherical microstructure of the carbon-based fillers acts as a solid lubricant during drill bit contact, reducing frictional resistance between the drill bit and the adhesive film, thus facilitating a reduction in drilling torque.

[0149] Oxide and hydroxide fillers include silica, aluminum oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium silicate, titanium dioxide, magnesium oxide, and calcium oxide. These fillers are characterized by high hardness and high chemical stability. Silica and aluminum oxide, as rigid skeleton fillers, form the core nodes of the stress dispersion network in the rigid filler layer 30, transforming point stress into a planar distribution due to their high elastic modulus. Aluminum hydroxide decomposes and absorbs heat when heated, releasing water of crystallization, endowing the rigid filler layer 30 or surface contact layer 40 with intrinsic flame-retardant properties, suitable for scenarios requiring suppression of heat buildup during high-temperature processing. Calcium carbonate, magnesium carbonate, and magnesium silicate are low-cost and have good filling properties, suitable for cost-sensitive large-scale applications. Titanium oxide, magnesium oxide, and calcium oxide combine filling and functionality—the high refractive index of titanium oxide facilitates the identification of the film position during optical inspection, while the high thermal conductivity of magnesium oxide and calcium oxide aids in heat diffusion.

[0150] Nitride and carbide fillers include silicon carbide, titanium carbide, boron nitride, and aluminum nitride. These fillers share the common characteristic of combining high hardness with excellent thermal conductivity. Silicon carbide and titanium carbide have high Mohs hardness, providing excellent compressive support in the rigid filler layer 30; boron nitride and aluminum nitride have high thermal conductivity, effectively conducting heat during drilling and preventing support failure caused by localized overheating and softening of the adhesive film.

[0151] Thermally expandable foaming materials are functional fillers that maintain a solid microsphere morphology at room temperature. When heated to a specific temperature, the outer shell of the microspheres softens, and the internal hydrocarbon foaming agent vaporizes and expands, increasing the volume of the microspheres by tens of times. Introducing thermally expandable foaming materials into the surface contact layer 40 can trigger foaming during the heating stage before peeling. After the microspheres expand, microscopic undulations are formed at the contact interface between the surface contact layer 40 and the substrate, reducing the actual contact area and helping to reduce the peeling force.

[0152] It is understood that by limiting the inorganic filler to at least one of the above types, the rigid filler layer 30 and the surface contact layer 40 can select a suitable filler system according to the processing conditions and performance focus, so as to provide rigid support while taking into account functions such as heat conduction, flame retardancy or peeling assistance.

[0153] In some embodiments, the particle size of the first inorganic filler and / or the second inorganic filler is between 0.1 μm and 100 μm.

[0154] Specifically, the particle size of inorganic fillers directly affects their dispersion state, packing density, and microscopic smoothness of the layer surface in the resin matrix. A lower particle size limit of 0.1 μm defines a safe boundary from the perspective of dispersion stability—when the filler particle size is less than 0.1 μm, the specific surface area of ​​the particles increases sharply, the surface free energy rises significantly, and spontaneous agglomeration occurs between particles due to van der Waals forces, forming hard agglomerates that are difficult to disperse in the resin matrix, leading to localized stress concentration and deterioration of mechanical properties in the layer. An upper particle size limit of 100 μm defines a safe boundary from the perspective of film quality and processing accuracy—when the filler particle size is greater than 100 μm, the geometric size of a single particle is close to or exceeds the thickness of the rigid filler layer 30 or the surface contact layer 40. During the coating and film formation process, the particles protrude from the layer surface, causing surface roughness deterioration and affecting the uniform contact between the layer and the substrate surface during adhesion; during drilling, large-diameter particles may detach from the resin matrix under the shearing force of the drill bit, forming debris at the hole opening.

[0155] By limiting the particle size range to 0.1 μm to 100 μm, the inorganic filler can be uniformly dispersed in the resin matrix and form a dense particle packing structure, providing a geometric basis for the construction of the stress dispersion network. For example, the particle size of the inorganic filler can be 0.5 μm, 2 μm, 10 μm, 30 μm, 50 μm, 70 μm, or 90 μm.

[0156] It is understandable that by limiting the particle size of inorganic fillers within the aforementioned specific range, a balance is established between dispersibility and film-forming properties—the lower particle size limit ensures that the fillers do not spontaneously agglomerate, while the upper particle size limit ensures that the filler particles do not damage the surface smoothness and structural integrity of the layer, thus guaranteeing the uniformity and reliability of the stress dispersion network.

[0157] In some embodiments, the surface of the first inorganic filler and / or the second inorganic filler is modified with at least one functional group selected from aniline, alkyl, nitrogen-containing functional groups, double-bonded functional groups and epoxy groups.

[0158] Specifically, surface functional group modification of inorganic fillers involves introducing specific functional groups onto the surface of filler particles through chemical grafting or physical adsorption to improve the interfacial compatibility and bonding strength between the filler and the resin matrix. Unmodified inorganic fillers typically have polar groups such as hydroxyl groups distributed on their surfaces, making them prone to agglomeration through hydrogen bonding. Furthermore, the interfacial bonding between polar surfaces and non-polar or weakly polar resin matrices is weak, making the filler particles easily detach from the resin matrix under external stress.

[0159] The aniline- and nitrogen-containing functional group-modified fillers introduce nitrogen atoms with lone pairs of electrons into their surface, enabling them to form hydrogen bonds or dipole interactions with polar functional groups such as epoxy groups or carboxyl groups in the resin matrix, thus enhancing the interfacial anchoring between the filler and the resin matrix. Alkyl modification, by grafting long-chain alkyl groups onto the filler surface, reduces the polarity of the filler surface, improving its compatibility with low-polarity thermoplastic resin matrices and increasing the uniformity of filler dispersion in the resin matrix. Double-bond functional group modification introduces unsaturated bonds into the filler surface that can participate in free radical or addition reactions. During the thermosetting stage, these double bonds can chemically react with active functional groups in the resin matrix, forming covalent bridges between the filler and the resin matrix. Epoxy group modification introduces epoxy functional groups into the filler surface. During the thermosetting stage, these epoxy groups can participate in the ring-opening crosslinking reaction of the resin matrix, anchoring the filler particles covalently within a three-dimensional crosslinked network.

[0160] It is understandable that by modifying the functional groups on the surface of inorganic fillers, the interfacial bonding between the fillers and the resin matrix is ​​upgraded from simple physical intercalation to chemical bonding or strong polar anchoring. During drilling, the filler particles are not easily detached from the resin matrix, and during peeling, the fillers are completely removed along with the resin matrix, ensuring the structural integrity of the film under high stress processing conditions.

[0161] In some embodiments, the adhesive layer 20 comprises a vinyl chloride-vinyl acetate copolymer resin.

[0162] Specifically, the chlorinated vinyl acetate copolymer resin is a thermoplastic resin obtained by chlorinating and modifying ethylene-vinyl acetate copolymer. During the chlorination modification process, chlorine atoms partially replace hydrogen atoms in the molecular chain segments of the ethylene-vinyl acetate copolymer, introducing highly polar carbon-chlorine bonds into the molecular chain segments. This change in chemical structure endows the chlorinated vinyl acetate copolymer resin with several properties that distinguish it from unmodified ethylene-vinyl acetate copolymer, enabling it to play a crucial functional role in the adhesive layer 20.

[0163] From a molecular structure perspective, the vinyl chloride-vinyl acetate copolymer resin molecular chains contain both polar ester groups provided by the vinyl acetate segments and carbon-chlorine bonds introduced through chlorination modification. The carbonyl oxygen atoms in the ester groups can form hydrogen bonds or dipole-dipole interactions with polar functional groups on the surface of the substrate layer 10 or oxygen-containing groups introduced after corona treatment, establishing a strong interfacial physical anchor between the adhesive layer 20 and the substrate layer 10. The introduction of carbon-chlorine bonds increases the polarity and cohesive energy density of the molecular chains, improving the wettability of the vinyl chloride-vinyl acetate copolymer resin on the surface of the substrate layer 10. During coating or lamination processes, the resin melt can fully spread and penetrate into the microscopic uneven structure of the substrate layer 10 surface, forming a mechanical interlocking effect. Simultaneously, the carbon-chlorine bonds also endow the vinyl chloride-vinyl acetate copolymer resin with certain flame-retardant properties; chlorine atoms can capture active free radicals in the combustion chain reaction at high temperatures, slowing down the combustion process of the material.

[0164] From the perspective of interlayer compatibility, the adhesive layer 20 is located between the substrate layer 10 and the rigid filler layer 30 in the film stack. Its upper surface is in contact with the corona-treated surface of the substrate layer 10, and its lower surface is in contact with the rigid filler layer 30. The substrate layer 10 is typically selected from polar or non-polar polymer films such as polyethylene terephthalate, polyimide, or polyolefin. The rigid filler layer 30 contains a first thermoplastic material and a highly loaded first inorganic filler. The surface chemical properties and mechanical modulus of the two are significantly different. The vinyl chloride-vinyl acetate copolymer resin, with its coexistence structure of polar groups and non-polar backbone in its molecular chain segments, exhibits good wetting and adhesion capabilities to both the polar surface of the substrate layer 10 and the weakly polar surface of the thermoplastic material in the rigid filler layer 30, thus playing a role in chemical compatibility bridging between the two layers.

[0165] From a mechanical perspective, the Young's modulus of the substrate layer 10 is typically higher than that of the rigid filler layer 30, resulting in differences in their deformation responses under external mechanical stress. If the substrate layer 10 and the rigid filler layer 30 are in direct contact, shear stress concentration will occur at the interface due to modulus mismatch under the instantaneous impact load of drilling, easily leading to interlayer delamination. The molecular chain segments of the vinyl chloride-vinyl acetate copolymer resin have moderate flexibility. The adhesive layer 20 acts as a modulus transition buffer layer between the substrate layer 10 and the rigid filler layer 30, creating a gradual mechanical transition between the high modulus of the substrate layer 10 and the lower modulus of the rigid filler layer 30, reducing shear stress concentration at the interface, and ensuring the interlayer structural integrity of the adhesive film during processing.

[0166] It is understandable that by introducing ethylene chloride-vinyl acetate copolymer resin into the adhesive layer 20, and utilizing the synergistic effect of the polar ester groups and carbon-chlorine bonds in its molecular chain segments, a connection interface with both chemical anchoring and mechanical buffering functions is established between the substrate layer 10 and the rigid filler layer 30. The adhesive layer 20 maintains its interlayer bonding force during attachment and drilling processes, and is removed as a whole along with the substrate layer 10 during peeling, ensuring the structural reliability of the adhesive film under high-stress processing conditions.

[0167] In some embodiments, the adhesive layer 20 further comprises a hot-melt ethylene-vinyl acetate copolymer resin and / or an epoxy resin.

[0168] Specifically, hot-melt ethylene-vinyl acetate copolymer resin and epoxy resin are optional additional components of the adhesive layer 20. Each, based on the basic framework of ethylene-vinyl acetate copolymer resin, specifically adjusts the hot processability, initial tack, and curing behavior of the adhesive layer 20. Depending on the performance emphasis of the adhesive layer 20 in the actual application scenario, hot-melt ethylene-vinyl acetate copolymer resin, epoxy resin, or both can be introduced alone.

[0169] Hot-melt ethylene-vinyl acetate copolymer resin is a thermoplastic resin that is solid at room temperature, melts and flows after heating above its softening point, and returns to a solid state upon cooling. Compared with chlorinated ethylene-vinyl acetate copolymer resin, hot-melt ethylene-vinyl acetate copolymer resin does not contain chlorine atoms in its molecular chain segments, has relatively low polarity, but exhibits superior melt flowability. When hot-melt ethylene-vinyl acetate copolymer resin is introduced into the adhesive layer 20, it melts first under heating conditions during coating or lamination, reducing the melt viscosity of the entire adhesive layer 20 formulation and facilitating the spreading and penetration of chlorinated ethylene-vinyl acetate copolymer resin on the surface of the substrate layer 10. After cooling, the hot-melt ethylene-vinyl acetate copolymer resin and the chlorinated ethylene-vinyl acetate copolymer resin form physical entanglements at the molecular chain segment scale, jointly constituting a continuous phase network of the adhesive layer 20. During the bonding heating stage, the hot-melt ethylene-vinyl acetate copolymer resin remelts, providing a certain thermal fluidity for the adhesive layer 20, and assisting the overall film to conform to the high-displacement morphology of the substrate surface.

[0170] Epoxy resin is a thermosetting oligomer containing two or more epoxy groups in its molecular chain segment. When epoxy resin is introduced into the adhesive layer 20, it exists in the adhesive layer 20 as an uncured oligomer during the coating and bonding stages. At this stage, the epoxy resin has a low molecular weight, which helps regulate the melt viscosity and initial tack of the adhesive layer 20. During the heating or post-curing stage after film bonding, the epoxy groups of the epoxy resin undergo a ring-opening cross-linking reaction under the action of the curing agent, constructing a three-dimensional cross-linked network within the adhesive layer 20. The establishment of this cross-linked network significantly improves the cohesive strength and heat resistance of the adhesive layer 20, allowing it to maintain structural integrity under the high temperature and shear stress conditions of subsequent drilling operations, without interlayer slippage or cohesive failure.

[0171] It is understood that by introducing hot-melt ethylene-vinyl acetate copolymer resin and / or epoxy resin as optional additional components into the adhesive layer 20, the hot processing fluidity, initial tack and final cured strength of the adhesive layer 20 can be flexibly adjusted according to processing conditions and performance requirements, providing formulation design space for the interlayer reliability of the film in different application scenarios.

[0172] In some embodiments, when the adhesive layer 20 comprises a hot-melt ethylene-vinyl acetate copolymer resin, the hot-melt ethylene-vinyl acetate copolymer resin includes at least one of reactive polyurethane hot melt adhesive, polyamide hot melt adhesive, polyolefin hot melt adhesive, ethylene-vinyl acetate copolymer hot melt adhesive, polyethylene hot melt adhesive, and polypropylene hot melt adhesive.

[0173] Specifically, all of the above-mentioned hot melt resins have the behavioral characteristics of melting and flowing under heating conditions, curing after cooling, and forming a film layer with a certain cohesive strength, but their chemical structures and application characteristics have different focuses.

[0174] Reactive polyurethane hot melt adhesives primarily consist of isocyanate-terminated polyurethane prepolymers. After being heated and melted for application, the isocyanate groups chemically react with moisture in the air or hydroxyl groups on the substrate surface, forming a high-molecular-weight polyurethane-urea crosslinked network. This "moisture-curing" mechanism allows the reactive polyurethane hot melt adhesive to provide strength not only through physical phase changes after cooling but also through chemical crosslinking, further enhancing its cohesive strength and heat resistance. The adhesive layer 20 incorporating the reactive polyurethane hot melt adhesive achieves durable interlayer bonding during the curing stage after application, maintaining structural stability during high-temperature drilling.

[0175] Polyamide hot melt adhesives are primarily composed of polyamide resins obtained through the condensation polymerization of dimer acids and diamines. The hydrogen bonding of amide groups in the molecular chain endows polyamide hot melt adhesives with excellent strength, toughness, and good adhesion to polar surfaces. Polyamide hot melt adhesives have a relatively high softening point, making them suitable for applications requiring sustained bond strength at high processing temperatures.

[0176] Polyolefin hot melt adhesives are based on ethylene-propylene copolymers or other polyolefins. Their molecular chains contain no polar groups, resulting in low surface energy, good wetting properties on non-polar substrates, and excellent water and chemical resistance. Ethylene-vinyl acetate copolymer hot melt adhesives are based on a copolymer of ethylene and vinyl acetate. Their softness, polarity, and adhesion can be controlled by adjusting the vinyl acetate content, making them one of the most widely used types of hot melt adhesives. Polyethylene and polypropylene hot melt adhesives are based on low molecular weight polyethylene or polypropylene, respectively. They have low melt viscosity and good flowability, making them suitable for coating processes requiring rapid wetting and spreading.

[0177] It is understood that by limiting the hot-melt ethylene-vinyl acetate copolymer resin to at least one of the above types, the thermal processing characteristics and final mechanical properties of the adhesive layer 20 can be specifically selected according to the material of the substrate layer 10, the bonding process conditions and the drilling temperature.

[0178] In some embodiments, when the adhesive layer 20 comprises epoxy resin, the adhesive layer 20 further comprises phenolic resin as a curing agent for the epoxy resin, wherein the content of the phenolic resin satisfies the following dependency relationship:

[0179] Phenolic resin content = (hydroxyl equivalent of phenolic resin / epoxy equivalent of epoxy resin) × epoxy resin content.

[0180] Specifically, phenolic resin, as a curing agent for epoxy resin, undergoes a nucleophilic addition ring-opening reaction between the phenolic hydroxyl groups in the phenolic resin molecular chain and the epoxy groups in the epoxy resin molecular chain. In this reaction, one phenolic hydroxyl group consumes one epoxy group on a theoretical stoichiometric basis. When the two react in an equimolar ratio, the crosslinking network of the epoxy resin reaches the ideal crosslinking density, and the cured product exhibits optimal mechanical strength, heat resistance, and chemical resistance.

[0181] The aforementioned dependency relationship is established based on this equivalence stoichiometry principle. In the relationship, the hydroxyl equivalent of the phenolic resin represents the number of moles of active phenolic hydroxyl groups per unit mass of phenolic resin, and the epoxy equivalent of the epoxy resin represents the number of moles of active epoxy groups per unit mass of epoxy resin. By calculating the ratio of the hydroxyl equivalent of the phenolic resin to the epoxy equivalent of the epoxy resin, and then multiplying it by the actual amount of epoxy resin added, the theoretical amount of phenolic resin required for complete reaction of the epoxy groups can be determined.

[0182] If the actual amount of phenolic resin added is lower than the theoretical value calculated by the above formula, there are insufficient active sites for phenolic hydroxyl groups in the cured system, and some epoxy groups cannot undergo ring-opening crosslinking, leaving unreacted epoxy oligomer segments in the crosslinking network. These residual oligomers act as plasticizers in the crosslinking network, leading to a decrease in the glass transition temperature, a reduction in Young's modulus, and a deterioration in heat resistance after the adhesive layer 20 is cured. If the actual amount of phenolic resin added is higher than the theoretical value, there are excessive free phenolic hydroxyl groups in the system. These free phenolic hydroxyl groups remain in the crosslinking network after curing, and due to their strong polarity, they significantly increase the intrinsic water absorption rate of the adhesive layer 20, easily causing interlayer moisture stratification in subsequent wet processes or humid heat aging environments.

[0183] It is understandable that by strictly limiting the stoichiometric ratio of the phenolic resin content according to the above-mentioned dependence formula, the curing reaction between epoxy resin and phenolic resin achieves an equivalence match of active functional groups. The crosslinking density, mechanical strength and damp heat resistance of the adhesive layer 20 after curing are reliably guaranteed, providing a chemical basis for the interlayer integrity of the film in subsequent drilling and damp heat processes.

[0184] In some embodiments, the epoxy resin is selected from at least one of glycidylamine epoxy resin, phenoxy resin, polyfunctional o-cresol glycidyl ether epoxy resin, phenol-biphenyl epoxy resin, bisphenol F solid epoxy resin, isocyanate modified epoxy resin, naphthol type epoxy resin, phenol-formaldehyde epoxy resin, semi-crystalline epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, liquid bisphenol S epoxy resin, and liquid phenolic epoxy resin.

[0185] Specifically, the aforementioned epoxy resins can be classified into five categories based on their molecular skeleton structure: glycidylamine type, phenolic type, bisphenol type, naphthalene type, and modified type. Glycidylamine epoxy resins contain aromatic amine structures and multiple epoxy groups in their molecular chain segments, exhibiting high functionality and high crosslinking density after curing, thus imparting excellent high-temperature rigidity to the adhesive layer. Multifunctional o-cresol-aldehyde glycidyl ether type epoxy resins and phenolic epoxy resins both belong to the phenolic type epoxy resin category. Their molecular chain segments contain multiple epoxy groups, forming a highly crosslinked three-dimensional network after curing, exhibiting outstanding heat resistance and dimensional stability. Phenolic-biphenyl epoxy resins introduce a rigid biphenyl structure into the molecular skeleton, resulting in a high flexural modulus and low water absorption in the cured product. Bisphenol F solid epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, and liquid bisphenol S epoxy resin all belong to the bisphenol type epoxy resin category. Solid grades provide film-forming rigidity, while liquid grades reduce system viscosity and improve wetting and spreading ability on substrate surfaces. Naphthol-type epoxy resins, with naphthalene rings as the backbone, exhibit excellent heat and moisture resistance after curing. Isocyanate-modified epoxy resins, by introducing oxazolidinone ring structures, enhance adhesion to metal substrate surfaces. Phenoxy resins are high-molecular-weight linear epoxy resins that do not participate in crosslinking reactions but can improve the film-forming flexibility of uncured adhesive layers. Semi-crystalline epoxy resins partially crystallize at room temperature, providing initial hardness and cold flow resistance to uncured adhesive layers.

[0186] It is understood that by limiting the epoxy resin to at least one of the above types, it can be selected or compounded according to the different requirements of the adhesive layer 20 for crosslinking density, heat resistance, flexibility and substrate wettability.

[0187] In some embodiments, the phenolic resin is selected from at least one of linear phenol-formaldehyde resin and linear bisphenol A-formaldehyde resin.

[0188] Specifically, linear phenol-formaldehyde resin is formed by the condensation polymerization of phenol and formaldehyde under acidic conditions. The phenol units are linked by methylene groups in the molecular chain, resulting in a high density of phenolic hydroxyl groups, strong reactivity, and rapid crosslinking speed when cured with epoxy resin. The cured product exhibits high crosslinking density and excellent heat resistance. Linear bisphenol A-formaldehyde resin uses bisphenol A instead of phenol in the condensation polymerization of formaldehyde. Isopropyl bridging bonds are introduced into the molecular backbone, maintaining the reactivity of the phenolic hydroxyl groups while imparting a certain degree of flexibility to the cured product and reducing the internal stress of the crosslinking network.

[0189] It is understood that by limiting the phenolic resin to at least one of the above types, it can be selected according to the requirements of curing speed, crosslinking density and final mechanical properties, and synergistically construct a high-performance curing network of the adhesive layer 20 with the epoxy resin.

[0190] In some embodiments, the content of ethylene chloride-vinyl acetate copolymer resin is between 5 wt% and 100 wt% based on the total weight of the adhesive layer 20.

[0191] Specifically, the vinyl chloride-vinyl acetate copolymer resin is used as the base resin component of the adhesive layer 20, and its content limit of 5 wt% defines the effectiveness boundary from the perspective of interfacial anchoring function. When the content of vinyl chloride-vinyl acetate copolymer resin is less than 5 wt%, the density of polar ester groups and carbon-chlorine bonds in the adhesive layer 20 is insufficient to establish effective chemical anchoring and mechanical buffering between the substrate layer 10 and the rigid filler layer 30, resulting in a significant decrease in interlayer bonding strength and easy interlayer delamination under the shear stress of drilling. The upper limit of 100 wt% corresponds to the scheme in which the adhesive layer 20 is composed of only a single component of vinyl chloride-vinyl acetate copolymer resin. In this case, the adhesive layer 20 functions with all the properties of this resin, without introducing hot-melt vinyl chloride-vinyl acetate copolymer resin or epoxy resin. For example, the content of vinyl chloride-vinyl acetate copolymer resin can be 10 wt%, 25 wt%, 40 wt%, 60 wt%, 80 wt%, or 100 wt%.

[0192] It is understandable that by limiting the content of ethylene chloride-vinyl acetate copolymer resin to 5wt% to 100wt%, while ensuring the basic interface anchoring function of the adhesive layer 20, room for formula adjustment is left for the introduction of hot-melt ethylene-vinyl acetate copolymer resin and epoxy resin.

[0193] In some embodiments, when the adhesive layer 20 comprises a hot-melt ethylene-vinyl acetate copolymer resin, the content of the hot-melt ethylene-vinyl acetate copolymer resin is not greater than 75 wt% based on the total weight of the adhesive layer 20.

[0194] Specifically, the main function of the hot-melt ethylene-vinyl acetate copolymer resin in the adhesive layer 20 is to improve thermal processing flowability and initial tack. When the content of the hot-melt ethylene-vinyl acetate copolymer resin exceeds 75 wt%, the proportion of polar components in the adhesive layer 20 is excessively diluted, and the polar anchoring and mechanical buffering functions provided by the ethylene-vinyl acetate copolymer resin are significantly weakened. Simultaneously, an excessively high content of the hot-melt ethylene-vinyl acetate copolymer resin results in an excessively low melt viscosity of the adhesive layer 20 during the application heating stage. Under pressure, the resin flows excessively, overflowing from the edges of the adhesive film and contaminating the substrate surface or the drilling area. Limiting the content of the hot-melt ethylene-vinyl acetate copolymer resin to no more than 75 wt% ensures the basic anchoring strength and shape stability of the adhesive layer 20 while maintaining its auxiliary flow and initial tack adjustment functions. For example, when the adhesive layer 20 contains a hot-melt ethylene-vinyl acetate copolymer resin, its content can be 5wt%, 15wt%, 30wt%, 50wt%, 60wt%, or 75wt%.

[0195] It is understandable that by limiting the content of the hot-melt ethylene-vinyl acetate copolymer resin to no more than 75 wt%, a balance is established between processing fluidity and interlayer bonding strength, avoiding damage to the anchoring function of the adhesive layer 20 due to excessive dilution of the polar components.

[0196] In some embodiments, when the adhesive layer 20 contains epoxy resin, the content of epoxy resin is not more than 20 wt% based on the total weight of the adhesive layer 20.

[0197] Specifically, the role of epoxy resin in the adhesive layer 20 is to construct a three-dimensional cross-linked network after curing, thereby improving the final cohesive strength and heat resistance of the adhesive layer 20. When the epoxy resin content exceeds 20 wt%, the cross-linking density of the cured adhesive layer 20 is too high, significantly increasing its brittleness. During the film winding, cutting, or bending process, the overly brittle adhesive layer 20 is prone to microcracks. These cracks further propagate under the vibration and impact of subsequent drilling, leading to interlayer delamination or localized failure. Simultaneously, epoxy resin in its uncured state is a low molecular weight oligomer; excessively high content increases the cold flow of the uncured adhesive layer 20, exacerbating the risk of edge overflow during storage or transportation at room temperature. Limiting the epoxy resin content to no more than 20 wt% provides the adhesive layer 20 with curing reinforcement while maintaining a balance between the storage stability and processing operability of the uncured film. For example, when the adhesive layer 20 contains epoxy resin, its content can be 1 wt%, 3 wt%, 5 wt%, 10 wt%, 15 wt%, or 20 wt%.

[0198] It is understandable that by limiting the epoxy resin content to no more than 20 wt%, a balance is struck between curing enhancement and the workability of the uncured film, avoiding brittle failure and cold overflow problems caused by excessive cross-linking.

[0199] In some embodiments, the thickness of the adhesive layer 20 is between 0.0005 mm and 0.1 mm.

[0200] Specifically, the lower limit of the adhesive layer 20 thickness, 0.0005 mm, is defined from the perspective of film continuity and interface coverage integrity. When the thickness of the adhesive layer 20 is less than 0.0005 mm, the resin melt cannot form a continuous and uniform film on the surface of the substrate layer 10 during the coating process. Local areas may experience substrate exposure or film breakage, resulting in direct contact between the substrate layer 10 and the rigid filler layer 30 in defective areas. This leads to uneven distribution of interlayer bonding force, which becomes the starting point for interlayer delamination during drilling. The upper limit of the thickness, 0.1 mm, is defined from the perspective of mechanical transfer efficiency and overall film thickness control. When the thickness of the adhesive layer 20 exceeds 0.1 mm, the adhesive layer 20 itself forms an excessively long stress transmission path in the Z-axis direction. Furthermore, the thermal expansion of an excessively thick adhesive layer 20 increases at drilling temperatures, leading to increased interlayer thermal stress accumulation and exacerbating the risk of interlayer delamination. The thickness of the adhesive layer 20 is limited to 0.0005 mm to 0.1 mm to maintain a reasonable length of stress transmission path while satisfying film continuity and interface coverage integrity. For example, the thickness of the adhesive layer 20 can be 0.001 mm, 0.005 mm, 0.01 mm, 0.03 mm, 0.05 mm, or 0.08 mm.

[0201] It is understood that by limiting the thickness of the adhesive layer 20 within the aforementioned specific range, a balance is established between film formation continuity and mechanical transfer efficiency, ensuring the functional reliability of the adhesive layer 20 in the film stack.

[0202] In some embodiments, the vinyl chloride-vinyl acetate copolymer resin satisfies at least one of the following parameters: chlorine content between 10% and 70%, vinyl acetate content between 5% and 50%, softening point between 40°C and 120°C, tensile strength not less than 1 MPa, and elongation at break not less than 200%.

[0203] Specifically, the above parameters synergistically define the performance boundaries of the vinyl chloride-vinyl acetate copolymer resin from three dimensions: polarity anchoring capability, thermal processability, and mechanical reliability. Chlorine content characterizes the degree of chlorination; a lower limit of 10% ensures sufficient carbon-chlorine bond density to enhance resin polarity and wetting and anchoring effect on the substrate layer 10, while an upper limit of 70% prevents dechlorination degradation during high-temperature processing due to excessive chlorine atom density. Vinyl acetate content determines the density of ester group anchoring points in the molecular chain segments; a lower limit of 5% ensures basic interfacial anchoring capability, while an upper limit of 50% prevents excessively low softening points from affecting interlayer stability during drilling. A lower softening point of 40℃ ensures no cold flow or overflow of the film during room temperature storage and transportation, while an upper limit of 120℃ ensures sufficient resin melting and film formation at conventional coating or lamination temperatures. Tensile strength of not less than 1 MPa ensures the resin possesses basic cohesive strength to resist peeling forces, and elongation at break of not less than 200% ensures the resin's ability to adapt to deformation during film bending or peeling. For example, the chlorine content can be 15%, 25%, 40%, 55%, or 65%; the vinyl acetate content can be 10%, 20%, 30%, 40%, or 48%; the softening point can be 50°C, 65°C, 80°C, 95°C, or 115°C; the tensile strength can be 2 MPa, 5 MPa, or 10 MPa; and the elongation at break can be 300%, 600%, or 1000%.

[0204] In some embodiments, the hot-melt ethylene-vinyl acetate copolymer resin satisfies at least one of the following parameters: vinyl acetate content between 18% and 33%, softening point between 40°C and 200°C, tensile strength not less than 1 MPa, and elongation at break not less than 200%.

[0205] Specifically, the above parameters synergistically define the performance boundaries of the hot-melt ethylene-vinyl acetate copolymer resin from three dimensions: flexibility, processing window, and mechanical reliability. A lower limit of 18% vinyl acetate content ensures the resin has sufficiently low crystallinity and adequate flexibility, providing effective auxiliary flowability for the adhesive layer 20 during the bonding stage; an upper limit of 33% avoids insufficient cohesive strength due to excessive vinyl acetate content, leading to cohesive failure during peeling. A lower limit of 40°C softening point ensures stability during room temperature storage, while an upper limit of 200°C covers a wide processing window from low-temperature bonding to high-temperature bonding. Tensile strength of not less than 1 MPa and elongation at break of not less than 200% respectively ensure the resin's basic cohesive strength and flexible adaptability. For example, the vinyl acetate content can be 20%, 25%, 28% or 30%; the softening point can be 55℃, 90℃, 130℃, 160℃ or 190℃; the tensile strength can be 2 MPa, 5 MPa or 8 MPa; and the elongation at break can be 300%, 600% or 1000%.

[0206] It is understood that by limiting the physical property parameters of ethylene chloride-vinyl acetate copolymer resin and hot-melt ethylene-vinyl acetate copolymer resin to the above-mentioned ranges, the performance of adhesive layer 20 in multiple dimensions such as polarity anchoring, hot processing fluidity, storage stability and peel integrity is synergistically guaranteed, providing a material parameter basis for the interlayer reliability of the film in different application scenarios.

[0207] In some embodiments, the substrate layer 10 has a first surface and a second surface disposed opposite to each other, the first surface being provided with an antistatic layer, the sheet resistivity of the antistatic layer being between 10Ω and 10Ω. 8 Ω, the adhesive layer 20 is disposed on the second surface, and the dyne value of the second surface is not less than 40.

[0208] Specifically, the two sides of the substrate layer 10 each play different functional roles. The first surface, during film transfer, cutting, and application, frequently comes into contact with and rubs against equipment rollers, nozzles, or guide plates, easily accumulating static electricity. The antistatic layer on the first surface controls the surface resistivity to between 10Ω and 10⁻⁶. 8 Within the Ω range, the accumulated static charge on the surface can be promptly conducted away through the conductive pathways in the antistatic layer, preventing secondary contamination of the substrate caused by electrostatic adsorption of airborne particles, and simultaneously preventing electrostatic discharge from damaging the gate circuits of sensitive components on the substrate. The surface resistivity is higher than 10Ω. 8 When the surface area is below Ω, static charge cannot be effectively conducted away. When the surface area is below 10Ω, the high content of conductive medium in the antistatic layer may affect the transparency or mechanical strength of the substrate layer 10. After corona treatment or chemical roughening modification, the dyne value of the second surface is increased to not less than 40, and the surface energy is significantly increased. During coating or lamination, the resin melt fully wets and spreads the high surface energy second surface, penetrating and filling the micro-uneven structure of the surface. After cooling and curing, a dual bonding interface of mechanical interlocking and polar anchoring is formed, preventing the adhesive layer 20 from peeling off from the surface of the substrate layer 10 during subsequent processing.

[0209] It is understandable that by configuring an antistatic layer and a high surface energy bonding surface on both sides of the substrate layer 10, the performance of the adhesive film in high-precision automated processing is guaranteed in terms of both electrostatic protection and interlayer bonding reliability.

[0210] In some embodiments, the substrate layer 10 comprises at least one of polyethylene terephthalate, polyethylene naphthalate, polyetherimide, polyphenylene sulfide, polyetheretherketone, nylon, polycarbonate, poly(p-phenylenebenzodioxazole), polyimide, polysulfone, polyphenylene sulfone, liquid crystal polymer, polymethylpentene, polyethylene succinate, biaxially oriented polypropylene, polypropylene, high-density polyethylene, polyolefin, cyclic olefin copolymer, and bismaleimide triazine resin.

[0211] Specifically, the aforementioned polymer materials can be classified into three categories based on their heat resistance and mechanical properties: general-purpose, engineering plastics, and high-performance. Polyethylene terephthalate (PET), polyethylene naphthalate (PET), and biaxially oriented polypropylene (BOPP) are general-purpose film materials. After biaxial stretching, their molecular chains are highly oriented, exhibiting excellent flatness and tensile strength in the thickness direction, making them suitable for cost-sensitive applications requiring moderate processing temperatures. Polycarbonate, nylon, polymethylpentene, polyethylene succinate (PEG), polypropylene, high-density polyethylene (HDPE), polyolefins, and cyclic olefin copolymers belong to the engineering plastic category, each with its own emphasis on rigidity, toughness, and chemical resistance. Polyetherimide, polyphenylene sulfide, polyether ether ketone, poly(p-phenylenebenzodioxazole), polyimide, polysulfone, polyphenylene sulfone, liquid crystal polymers and bismaleimide triazine resins are high-performance resins. Their main chains are rich in rigid structures such as aromatic rings, sulfone groups or imide rings. They have high glass transition temperatures and low coefficients of thermal expansion. They maintain dimensional stability during high-temperature drilling or high-temperature curing processes and do not experience thermal shrinkage or warping.

[0212] It is understood that by limiting the material of the substrate layer 10 to at least one of the above types, the substrate layer 10 can be selected according to the drilling temperature, bonding pressure and cost constraints, so that the substrate layer 10 can meet the requirements of different application scenarios in terms of rigid support and thermal dimensional stability.

[0213] In some embodiments, the substrate layer 10 satisfies at least one of the following parameters: surface roughness Ra of the second surface is between 0.05 μm and 0.5 mm, Shore hardness D is not less than 60, surface hardness is not less than HB, Young's modulus is between 0.1 GPa and 30 GPa, tensile strength is between 10 MPa and 4000 MPa, and thickness is between 0.009 mm and 0.3 mm.

[0214] Specifically, the above parameters synergistically define the performance boundaries of the substrate layer 10 from three dimensions: surface microstructure, overall mechanical rigidity, and geometric dimensions. A lower limit of 0.05 μm for surface roughness Ra ensures that the second surface, after corona treatment, has sufficient micro-undulations to form a mechanical interlock with the adhesive layer 20, while an upper limit of 0.5 mm prevents excessive roughness from causing residual air bubbles in depressions or insufficient film thickness at protrusions during coating. Shore hardness D of not less than 60 and surface hardness of not less than HB ensure that the substrate layer 10 provides stable support from the perspectives of indentation resistance and scratch resistance, preventing localized collapse when pressed by the nozzle of the forming machine or contacted by the drill bit. A lower limit of 0.1 GPa for Young's modulus ensures that the substrate layer 10 possesses basic rigidity to resist tensile and bending deformation, while an upper limit of 30 GPa prevents excessive stiffness from causing insufficient film flexibility and inability to conform to the macroscopic warping of the substrate during adhesion. A minimum tensile strength of 10 MPa ensures that the substrate layer 10 does not break under winding tension and adhesion stretching, while an upper limit of 4000 MPa covers the application requirements of high-strength films. A minimum thickness of 0.009 mm ensures the basic mechanical strength and operability of the substrate layer 10, while an upper limit of 0.3 mm prevents excessive overall film thickness from increasing thermal resistance and affecting the uniform heat conduction to the adhesive layer 20 and rigid filler layer 30 during adhesion. For example, the surface roughness Ra can be 0.1 μm, 0.5 μm, 2 μm, 10 μm, or 50 μm; the Young's modulus can be 0.5 GPa, 2 GPa, 8 GPa, 15 GPa, or 25 GPa; the tensile strength can be 50 MPa, 200 MPa, 800 MPa, 1500 MPa, or 3000 MPa; and the thickness can be 0.012 mm, 0.05 mm, 0.1 mm, 0.15 mm, or 0.25 mm.

[0215] It is understood that by limiting the various physical property parameters of the substrate layer 10 to the above-mentioned range, a comprehensive balance is established between surface anchoring effect, deformation resistance rigidity, operational strength and thermal conductivity, ensuring the functional reliability of the substrate layer 10 as a rigid skeleton of the adhesive film throughout the entire processing.

[0216] In some embodiments, the release layer 50 comprises at least one of polyethylene terephthalate, biaxially oriented polypropylene, polypropylene, high-density polyethylene, polyolefin, and polyimide.

[0217] Specifically, the aforementioned polymer film materials all possess characteristics of high surface density, strong chemical inertness, and low intrinsic surface energy. Polyethylene terephthalate (PET), after biaxial stretching, exhibits excellent surface smoothness and mechanical strength, making it the most commonly used substrate for release layer 50. Biaxially stretched polypropylene (BTP) has low density and good flexibility. Polypropylene and high-density polyethylene (HDPE) exhibit good intrinsic release properties to acrylate resins, allowing for direct use without release agent coating under light release force requirements. Polyimide demonstrates outstanding high-temperature resistance, making it suitable for applications where the film requires high-temperature baking or pre-curing. The surface of the release layer 50 substrate can be coated with silicone, fluorine, or long-chain alkane release agents according to release force requirements, allowing for precise control of the release force within the range of 3 g / mm to 500 g / mm.

[0218] In some embodiments, the release force of the release layer 50 is between 3 g / mm and 500 g / mm.

[0219] Specifically, the lower limit of the release force of 3 g / mm ensures that the release layer 50 does not spontaneously detach during winding, slitting, and transportation, while the upper limit of 500 g / mm ensures that the pulling force required to remove the release layer 50 is within the controllable range of the automated film-tearing equipment, avoiding local deformation of the surface contact layer 40 due to excessive peeling resistance. For example, the release force can be 10 g / mm, 50 g / mm, 120 g / mm, 250 g / mm, or 400 g / mm.

[0220] In some embodiments, the thickness of the release layer 50 is between 0.0005 mm and 0.1 mm.

[0221] Specifically, the lower limit of the release layer 50 thickness, 0.0005 mm, ensures the film has basic continuity and tensile strength, preventing breakage and residue during peeling. The upper limit, 0.1 mm, prevents excessive bending stiffness of the release layer 50, which could lead to wrinkles or uneven release force due to insufficient adhesion to the surface contact layer 40 during winding. For example, the thickness can be 0.001 mm, 0.008 mm, 0.025 mm, 0.05 mm, or 0.08 mm.

[0222] It is understood that by limiting the material, release force, and thickness of the release layer 50 to the above ranges, the release layer 50 provides reliable physical protection for the surface contact layer 40 during storage and transportation, and can be smoothly and completely removed with appropriate pulling force before use, thus ensuring the reliability of the bonding process.

[0223] The present invention also proposes a method for processing a substrate using a high breakage protection and anti-burr film as described in any of the preceding claims.

[0224] like Figure 2As shown, in one embodiment of the present invention, the processing method includes the following steps:

[0225] S10. Provide a substrate to be processed, the surface of which has a high-displacement structure.

[0226] Specifically, the high-displacement structure includes at least one of blind vias, countersunk holes, metal bumps, and copper pillars. This high-displacement structure creates a significant height difference on the substrate surface. During subsequent drilling, the hole edge is prone to burrs or deformation due to the lack of continuous and uniform physical support at the moment the drill bit penetrates the substrate. The substrate provided in this step is the object to be processed in subsequent bonding, drilling, and peeling processes.

[0227] S20. Attach the high-displacement protection and anti-burr film to the surface of the substrate, and then attach and fill the high-displacement structure by bonding the surface contact layer of the high-displacement protection and anti-burr film.

[0228] Specifically, before applying the high-breakage protection and burr-resistant adhesive film to the substrate surface, the processing method further includes: peeling the release layer from the high-breakage protection and burr-resistant adhesive film to expose the clean adhesive surface of the surface contact layer. The release force of the release layer is between 3 g / mm and 500 g / mm, requiring moderate tension during peeling. The peeling interface propagates along the contact surface between the release layer and the surface contact layer, and the release layer is completely removed without leaving any release agent or film fragments on the surface of the surface contact layer.

[0229] After the release layer is peeled off, the bonding step is performed under heating and pressure. Heating softens the first thermoplastic material in the rigid filler layer and the modified acrylic resin and second thermoplastic material in the surface contact layer, resulting in controlled plastic flow under pressure, allowing the adhesive film to adhere to the substrate surface as a whole. The surface contact layer, serving as the interface between the adhesive film and the substrate, conforms to the uneven morphology of the substrate surface under bonding pressure, penetrating and filling the bottom of blind vias, countersunk holes, and the micro-gaps between metal bumps or copper pillars. Following the surface contact layer, the rigid filler layer further fills the recessed areas of the high-displacement structure under the combined drive of heat and pressure, squeezing out residual air in the recesses.

[0230] After the adhesive film is applied, the surface contact layer and the rigid filler layer together form a continuous filler that fits tightly with the high discontinuity morphology on the substrate surface. The recessed structures such as blind holes and countersunk holes are fully filled, and the raised structures such as metal bumps and copper pillars are fully covered. After the adhesive film is applied, a flat processing surface is formed on the substrate surface, which provides uniform and continuous bottom support for subsequent drilling processing.

[0231] S30. Drilling is performed on a substrate with a high breakage protection and anti-burr film.

[0232] Specifically, before drilling, the high-breakage protection and burr-resistant adhesive film attached to the substrate is cooled to room temperature. Here, "room temperature" refers to the ambient temperature of the adhesive film before the attachment process, without heat or pressure treatment. For example, room temperature can be 15°C, 20°C, 25°C, or 30°C. In practice, the film temperature can be restored to the aforementioned room temperature range through natural cooling, forced air cooling, or contact cooling.

[0233] After cooling to room temperature, the first thermoplastic material in the rigid filler layer, which softened during the application heating stage, returns to a solid or highly elastic state. The stress-dispersing network formed by the first inorganic filler is re-fixed in the resin matrix, and the rigid filler layer returns to a rigid state with a surface hardness of not less than 6B. Similarly, the modified acrylic resin and the second thermoplastic material in the surface contact layer return to their room-temperature mechanical state, and the adhesive force and cohesive strength of the surface contact layer return to their intrinsic levels as designed. After cooling, the film possesses the rigid support and interfacial stability required for drilling.

[0234] During drilling, the drill bit enters from one side of the adhesive film's substrate layer or the other side of the substrate, penetrating both the adhesive film and the substrate. At the moment of drill contact, the stress-dispersing network formed by the first inorganic filler in the rigid filler layer transforms the point-like downward impact force applied by the drill bit into a planar distributed load, creating a stable pad-like clamping effect around the hole opening. The second inorganic filler in the surface contact layer acts as a microscopic rigid support point, transmitting the Z-axis mechanical stress applied by the drill bit downwards to the rigid filler layer. The substrate material at the hole edge remains under constrained pressure due to the tight adhesion and support of the adhesive film, preventing outward curling or plastic deformation, thus physically suppressing burr formation.

[0235] S40. After drilling is completed, peel the high-breakage protection and anti-burr film off the surface of the substrate.

[0236] Specifically, after drilling, the adhesive film has fulfilled its process protection function for the substrate. A peeling operation removes the adhesive film from the substrate surface. The adhesion strength of the surface contact layer ranges from 0.05 N / cm to 30 N / cm, requiring moderate tensile force during peeling. The peeling interface propagates along the contact surface between the surface contact layer and the substrate surface. The surface contact layer maintains its intact film morphology due to its sufficient cohesive strength, preventing cohesive fracture within the layer. After peeling, the substrate surface remains clean, with no visible or microscopic adhesive residue remaining in microscopic recesses such as blind vias, countersunk holes, or bump gaps.

[0237] In some embodiments, when the surface contact layer in the high-breakage protection and anti-burr film has debonding properties, the processing method of this application further includes applying a debonding activation treatment to the high-breakage protection and anti-burr film after drilling and before peeling off the high-breakage protection and anti-burr film, so as to reduce the adhesion force of the surface contact layer to no more than 2 N / cm.

[0238] Specifically, the debonding activation treatment method depends on the debonding mechanism of the modified acrylic resin in the surface contact layer. For example, when the modified acrylic resin is photosensitive crosslinking type, the debonding activation treatment involves ultraviolet irradiation. Ultraviolet light triggers a crosslinking reaction in the photosensitive functional groups within the resin matrix, causing the resin's free volume to shrink, surface energy to decrease, and adhesive strength to drop significantly. When the modified acrylic resin is mixed with thermally expanding microspheres or a thermally decomposing foaming agent, the debonding activation treatment involves heating to the foaming temperature. The expansion of the microspheres or the decomposition of the foaming agent produces gas, forming microscopic undulations at the interface between the surface contact layer and the substrate, reducing the actual contact area and thus lowering the adhesive strength.

[0239] Once the adhesive force is reduced to no more than 2 N / cm, only a very small mechanical pulling force is required to completely remove the adhesive film from the substrate surface during peeling. The peeling interface stably propagates along the contact surface between the surface contact layer and the substrate surface, further reducing the risk of mechanical damage to the substrate surface or the edge of the aperture caused by peeling.

[0240] It is understood that, through the above-described sequential steps of attachment, cooling, drilling, and peeling, the substrate processing method of this application embodiment utilizes the synergistic function of the rigid filling layer and the surface contact layer in the high-displacement protection and anti-burr film to achieve sufficient filling and tight coverage of the high-displacement morphology during the attachment stage, provide uniform and continuous rigid support to suppress burrs during the drilling stage, and achieve residue-free removal with controllable adhesive force during the peeling stage. This systematically solves the contradiction between filling, anti-burr, and peeling cleanliness in the drilling processing of high-displacement substrates from the process level.

[0241] This application also provides a substrate, which is obtained by the substrate processing method described in any of the preceding claims.

[0242] Specifically, after the bonding, drilling, and peeling processes, the substrate's surface—especially the area containing the high-displacement structure—exhibits physical characteristics distinct from traditional processing methods. At the edges of blind vias and countersunk holes, the rigid filling layer of the high-displacement protection and anti-burr adhesive film, along with the surface contact layer, provides continuous and uniform padding and support for the via material during drilling. The substrate material at the via edge remains under constrained pressure at the moment of drill penetration, without outward curling or plastic deformation. The via edge contour is regular, with no burrs or flash remaining. At the bottom of blind vias and countersunk holes, and in the microscopic gaps between metal bumps or copper pillars, the adhesive force of the surface contact layer is precisely controlled within the range of 0.05 N / cm to 30 N / cm during peeling. The peeling interface stably propagates along the contact surface between the surface contact layer and the substrate surface, resulting in the complete removal of the surface contact layer without any residual adhesive on the substrate surface. When the surface contact layer has debonding properties and the processing method includes a debonding activation step, the adhesive force of the surface contact layer before peeling has been reduced to no more than 2 N / cm, further reducing the risk of residual adhesive on the substrate surface.

[0243] It is understandable that the substrates obtained by the above processing method have better hole edge quality and surface cleanliness in the high-displacement structural area than substrates processed with traditional protective films, providing a high-quality substrate surface foundation for subsequent processes such as hole metallization, patterned electroplating, or component mounting.

[0244] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A high-breakage protective and anti-burr film, characterized in that, include: Substrate layer; An adhesive layer is disposed on one side surface of the substrate layer; A rigid filler layer is disposed on the side surface of the adhesive layer opposite to the substrate layer. The rigid filler layer comprises a first thermoplastic material and a first inorganic filler, and the surface hardness of the rigid filler layer is not less than 6B. as well as A surface contact layer is disposed on the side of the rigid filler layer opposite to the adhesive layer. The surface contact layer comprises a modified acrylic resin, a second thermoplastic material, and a second inorganic filler, and the adhesive force of the surface contact layer is between 0.05 N / cm and 30 N / cm.

2. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The surface contact layer satisfies at least one of the following conditions: The surface contact layer has de-adhesion properties, and the adhesive force after the surface contact layer is de-adhesion is not greater than 2 N / cm; The surface hardness of the surface contact layer is not less than 6B; The thickness of the surface contact layer is no greater than 0.1 mm.

3. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The rigid filler layer and / or the surface contact layer satisfy at least one of the following parameter conditions: Shore hardness ranges from 5 Shore A to 55 Shore D; Young's modulus ranges from 0.02 GPa to 1 GPa; Tensile strength ranges from 2 MPa to 60 MPa; The damage elongation rate ranges from 100% to 1500%.

4. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The thickness of the rigid filler layer is between 0.025 mm and 0.7 mm.

5. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The modified acrylic resin includes at least one of the following: waterborne acrylic emulsion resin, rubber-blended modified acrylic resin, silicone-modified acrylic resin, hydrophilic modified acrylic resin, homopolymer acrylic resin, copolymer acrylic resin, and thermally crosslinked acrylic resin.

6. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The first thermoplastic material and / or the second thermoplastic material includes at least one of polyvinyl butyral, ethylene-vinyl acetate copolymer, thermoplastic polyurethane, thermoplastic polyester elastomer, polyolefin elastomer, thermoplastic vulcanized rubber, styrene-based thermoplastic elastomer, thermoplastic nitrile rubber, olefin block copolymer, ionic thermoplastic elastomer, polyamide-based thermoplastic elastomer, ethylene glycol copolymerized modified polyethylene terephthalate, and low-density polyethylene.

7. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The first inorganic packing and / or the second inorganic packing satisfy at least one of the following conditions: It is selected from at least one of graphite, carbon black, graphene, fullerene, silicon dioxide, aluminum oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium silicate, silicon carbide, titanium carbide, titanium oxide, magnesium oxide, calcium oxide, boron nitride, aluminum nitride, and thermally expandable foaming materials; The particle size ranges from 0.1 μm to 100 μm; The surface is modified with at least one functional group selected from aniline, alkyl, nitrogen-containing functional group, double-bonded functional group and epoxy group.

8. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The adhesive layer comprises ethylene chloride-vinyl acetate copolymer resin.

9. The high-displacement protective and anti-burr film as described in claim 8, characterized in that, The adhesive layer further comprises a hot-melt ethylene-vinyl acetate copolymer resin and / or an epoxy resin.

10. The high-displacement protective and anti-burr film as described in claim 9, characterized in that, When the adhesive layer comprises a hot-melt ethylene-vinyl acetate copolymer resin, the hot-melt ethylene-vinyl acetate copolymer resin includes at least one of reactive polyurethane hot melt adhesive, polyamide hot melt adhesive, polyolefin hot melt adhesive, ethylene-vinyl acetate copolymer hot melt adhesive, polyethylene hot melt adhesive, and polypropylene hot melt adhesive.

11. The high-displacement protective and anti-burr film as described in claim 9, characterized in that, When the adhesive layer further comprises epoxy resin, the epoxy resin is selected from at least one of glycidylamine epoxy resin, phenoxy resin, polyfunctional o-cresol glycidyl ether epoxy resin, phenol-biphenyl epoxy resin, bisphenol F solid epoxy resin, isocyanate modified epoxy resin, naphthol type epoxy resin, phenol-formaldehyde epoxy resin, semi-crystalline epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, liquid bisphenol S epoxy resin, and liquid phenolic epoxy resin.

12. The high-displacement protective and anti-burr film as described in claim 9, characterized in that, When the adhesive layer comprises epoxy resin, the adhesive layer further comprises phenolic resin as a curing agent for the epoxy resin, wherein the content of the phenolic resin satisfies the following dependency relationship: Phenolic resin content = (hydroxyl equivalent of phenolic resin / epoxy equivalent of epoxy resin) × epoxy resin content.

13. The high-displacement protective and anti-burr film as described in claim 9, characterized in that, The adhesive layer satisfies at least one of the following conditions: The content of the ethylene chloride-vinyl acetate copolymer resin is between 5 wt% and 100 wt% based on the total weight of the adhesive layer. When the adhesive layer contains a hot-melt ethylene-vinyl acetate copolymer resin, the content of the hot-melt ethylene-vinyl acetate copolymer resin is not greater than 75 wt% based on the total weight of the adhesive layer. When the adhesive layer contains epoxy resin, the epoxy resin content, based on the total weight of the adhesive layer, is no more than 20 wt%. The thickness ranges from 0.0005 mm to 0.1 mm.

14. The high-displacement protective and anti-burr film as described in claim 9, characterized in that, The vinyl chloride-vinyl acetate copolymer resin satisfies at least one of the following parameters: chlorine content between 10% and 70%, vinyl acetate content between 5% and 50%, softening point between 40°C and 120°C, tensile strength not less than 1 MPa and elongation at break not less than 200%; and / or The hot-melt ethylene-vinyl acetate copolymer resin meets at least one of the following parameters: vinyl acetate content between 18% and 33%, softening point between 40°C and 200°C, tensile strength not less than 1 MPa, and elongation at break not less than 200%.

15. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The substrate layer has a first surface and a second surface disposed opposite to each other; The first surface is provided with an antistatic layer, the sheet resistance of which is between 10Ω and 10Ω. 8 Ω; The adhesive layer is disposed on the second surface, and the dyne value of the second surface is not less than 40.

16. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The substrate layer comprises at least one of polyethylene terephthalate, polyethylene naphthalate, polyetherimide, polyphenylene sulfide, polyetheretherketone, nylon, polycarbonate, poly(p-phenylenebenzodioxazole), polyimide, polysulfone, polyphenylene sulfone, liquid crystal polymer, polymethylpentene, polyethylene succinate, biaxially oriented polypropylene, polypropylene, high-density polyethylene, polyolefin, cyclic olefin copolymer and bismaleimide triazine resin.

17. The high-displacement protective and anti-burr film as described in claim 1, characterized in that, The substrate layer satisfies at least one of the following parameters: The surface roughness Ra of the second surface of the substrate layer is between 0.05 μm and 0.5 mm; Shore hardness D not less than 60; Surface hardness not less than HB; Young's modulus ranges from 0.1 GPa to 30 GPa; Tensile strength ranges from 10 MPa to 4000 MPa; The thickness ranges from 0.009 mm to 0.3 mm.

18. The high-breakage protective and anti-burr film as described in any one of claims 1 to 17, characterized in that, The high-displacement protective and anti-burr film also includes: A release layer is peelably disposed on the surface of the surface contact layer on the side opposite to the rigid filler layer.

19. The high-displacement protective and anti-burr film as described in claim 18, characterized in that, The release layer satisfies at least one of the following conditions: It contains at least one of polyethylene terephthalate, biaxially oriented polypropylene, polypropylene, high-density polyethylene, polyolefin and polyimide; Release force ranges from 3 g / mm to 500 g / mm; The thickness ranges from 0.0005 mm to 0.1 mm.

20. A method for processing a substrate, characterized in that, The processing method using the high breakage protection and anti-burr film as described in any one of claims 1 to 19 includes: A substrate to be processed is provided, the surface of which has a high-discontinuity structure; The high-displacement protection and anti-burr film are attached to the surface of the substrate, and the surface contact layer of the high-displacement protection and anti-burr film is bonded and filled to the high-displacement structure. Drilling is performed on the substrate to which the high-breakage protection and anti-burr film is applied; After the drilling process is completed, the high-displacement protection and anti-burr film is peeled off from the surface of the substrate.

21. The substrate processing method according to claim 20, characterized in that, Under heating and pressurization conditions, the high-breakage protection and anti-burr film is attached to the surface of the substrate; as well as Before performing the drilling process, the high-break protection and anti-burr film attached to the substrate is cooled to room temperature.

22. The substrate processing method as described in claim 20, characterized in that, When the surface contact layer in the high-breakage protection and anti-burr film has de-adhesion properties, the processing method further includes, after performing the drilling process and before peeling off the high-breakage protection and anti-burr film: The high-displacement protection and anti-burr film is subjected to a de-adhesion activation treatment to reduce the adhesion force of the surface contact layer to no more than 2 N / cm.

23. The method for processing a substrate according to any one of claims 20 to 22, characterized in that, The high-displacement structure includes at least one of blind holes, countersunk holes, metal bumps, and copper pillars.

24. A substrate, characterized in that, The substrate is obtained by the substrate processing method as described in any one of claims 20 to 23.

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